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Purcăreanu B, Ene MD, Moroșan A, Mihaiescu DE, Florea MA, Ghica A, Nita RA, Drumea V, Grigoroscuta MA, Kuncser A, Badica P, Olariu L. Mesoporous Composite Bioactive Compound Delivery System for Wound-Healing Processes. Pharmaceutics 2023; 15:2258. [PMID: 37765227 PMCID: PMC10534662 DOI: 10.3390/pharmaceutics15092258] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023] Open
Abstract
Currently, the treatment of wounds is still a challenge for healthcare professionals due to high complication incidences and social impacts, and the development of biocompatible and efficient medicines remains a goal. In this regard, mesoporous materials loaded with bioactive compounds from natural extracts have a high potential for wound treatment due to their nontoxicity, high loading capacity and slow drug release. MCM-41-type mesoporous material was synthesized by using sodium trisilicate as a silica source at room temperature and normal pressure. The synthesized mesoporous silica was characterized by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), N2 absorption-desorption (BET), Dynamic Light Scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR), revealing a high surface area (BET, 1244 m2/g); pore diameter of approx. 2 nm; and a homogenous, ordered and hexagonal geometry (TEM images). Qualitative monitoring of the desorption degree of the Salvia officinalis (SO) extract, rich in ursolic acid and oleanolic acid, and Calendula officinalis (CO) extract, rich in polyphenols and flavones, was performed via the continuous recording of the UV-VIS spectra at predetermined intervals. The active ingredients in the new composite MCM-41/sage and marigold (MCM-41/SO&CO) were quantified by using HPLC-DAD and LC-MS-MS techniques. The evaluation of the biological composites' activity on the wound site was performed on two cell lines, HS27 and HaCaT, naturally involved in tissue-regeneration processes. The experimental results revealed the ability to stimulate collagen biosynthesis, the enzymatic activity of the main metalloproteinases (MMP-2 and MMP-9) involved in tissue remodeling processes and the migration rate in the wound site, thus providing insights into the re-epithelializing properties of mesoporous composites.
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Affiliation(s)
- Bogdan Purcăreanu
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, Gh. Polizu 1-7, 011061 Bucharest, Romania
| | - Manuela Diana Ene
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
| | - Alina Moroșan
- Department of Organic Chemistry “Costin Neniţescu”, Faculty of Chemical Engineering and Biotechnologies, University POLITEHNICA of Bucharest, Gh. Polizu 1-7, 011061 Bucharest, Romania;
| | - Dan Eduard Mihaiescu
- Department of Organic Chemistry “Costin Neniţescu”, Faculty of Chemical Engineering and Biotechnologies, University POLITEHNICA of Bucharest, Gh. Polizu 1-7, 011061 Bucharest, Romania;
| | - Mihai Alexandru Florea
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
| | - Adelina Ghica
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
| | - Roxana Andreea Nita
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
| | - Veronica Drumea
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
| | - Mihai Alexandru Grigoroscuta
- National Institute of Materials Physics, Street Atomistilor 405 A, 077125 Magurele, Romania; (M.A.G.); (A.K.); (P.B.)
| | - Andrei Kuncser
- National Institute of Materials Physics, Street Atomistilor 405 A, 077125 Magurele, Romania; (M.A.G.); (A.K.); (P.B.)
| | - Petre Badica
- National Institute of Materials Physics, Street Atomistilor 405 A, 077125 Magurele, Romania; (M.A.G.); (A.K.); (P.B.)
| | - Laura Olariu
- Biotehnos SA, Gorunului Street 3-5, 075100 Otopeni, Romania or (B.P.); (M.A.F.); (A.G.); (R.A.N.); (V.D.); (L.O.)
- Academy of Romanian Scientists, 3 Ilfov Street, 030167, Bucharest, Romania
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Kuncser A, Vasylkiv O, Borodianska H, Demirskyi D, Badica P. High bending strength at 1800 °C exceeding 1 GPa in TiB 2-B 4C composite. Sci Rep 2023; 13:6915. [PMID: 37105994 PMCID: PMC10140271 DOI: 10.1038/s41598-023-33135-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
High density (99.5%) ceramic composite composed of titanium boride and boron carbide (70/30 vol%) was obtained by spark plasma sintering and was tested by 3-point bending test in Ar atmosphere at 1800 °C. Bending strength was high, around 1.1 GPa. The strength-strain curve presents a peculiar shape composed of three regions where elastic and plastic deformations are active with a different weight. Based on transmission electron microscopy observations we propose a process of mechanical energy absorption driven by shear stress in the boron carbide crystals: stacking faults with (1-11) and (011) stacking planes and twins with (1-11) twinning plane rearrange into nano-twins with (10-1) twinning planes, orthogonal but equivalent to the initial ones. This rearrangement mechanism provides in the first instance a plastic signature, but further contributes strengthening.
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Affiliation(s)
- A Kuncser
- National Institute of Materials Physics, Street Atomistilor 405 A, 077125, Magurele, Romania
| | - O Vasylkiv
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
| | - H Borodianska
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - D Demirskyi
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.
- Department of Materials Science and Engineering, Tohoku University, 6-6-02 Aramaki Aza Aoba, Sendai, 980-8579, Japan.
| | - P Badica
- National Institute of Materials Physics, Street Atomistilor 405 A, 077125, Magurele, Romania.
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Alimenti A, Torokhtii K, Vidal García P, Silva E, Grigoroscuta MA, Badica P, Crisan A, Pompeo N. Measurements of Surface Impedance in MgB 2 in DC Magnetic Fields: Insights in Flux-Flow Resistivity. Materials (Basel) 2022; 16:205. [PMID: 36614544 PMCID: PMC9822234 DOI: 10.3390/ma16010205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
We present the multifrequency measurements of the surface resistance of spark-plasma-sintered MgB2 performed through a dielectric loaded resonator operating at 16.5 and 26.7 GHz. By normally applying magnetic fields ≤1.2 T to the sample surface, we drove it in the mixed state. By means of data-rooted analysis, we found that the sample vortex dynamics could be fully described within a single-component approach. Pinning phenomena were present and characterized by a depinning frequency smaller than the measurement ones. The multiband nature of the superconductor emerged in the flux-flow resistivity, whose field dependence could be interpreted well within theoretical models. By exploiting them, the upper critical field was extracted in the low-temperature range, which exhibited a consistent temperature trend with the values obtained at the onset of the resistive transition near Tc, and was well in line with literature data on other polycrystalline samples.
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Affiliation(s)
- Andrea Alimenti
- Dipartimento di Ingegneria Industriale, Elettronica e Meccanica, Università degli Studi Roma Tre, Via Vito Volterra 62, 00146 Roma, Italy
| | - Kostiantyn Torokhtii
- Dipartimento di Ingegneria Industriale, Elettronica e Meccanica, Università degli Studi Roma Tre, Via Vito Volterra 62, 00146 Roma, Italy
| | - Pablo Vidal García
- Dipartimento di Ingegneria Industriale, Elettronica e Meccanica, Università degli Studi Roma Tre, Via Vito Volterra 62, 00146 Roma, Italy
| | - Enrico Silva
- Dipartimento di Ingegneria Industriale, Elettronica e Meccanica, Università degli Studi Roma Tre, Via Vito Volterra 62, 00146 Roma, Italy
- Istituto Nazionale di Fisica Nucleare–INFN, Sezione Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | | | - Petre Badica
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania
| | - Adrian Crisan
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania
| | - Nicola Pompeo
- Dipartimento di Ingegneria Industriale, Elettronica e Meccanica, Università degli Studi Roma Tre, Via Vito Volterra 62, 00146 Roma, Italy
- Istituto Nazionale di Fisica Nucleare–INFN, Sezione Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
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Velea A, Sava F, Badica P, Burdusel M, Mihai C, Galca AC, Matei E, Buruiana AT, El Khouja O, Calvez L. New Chalcogenide Glass-Ceramics Based on Ge-Zn-Se for IR Applications. Materials 2022; 15:ma15145002. [PMID: 35888469 PMCID: PMC9320402 DOI: 10.3390/ma15145002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/11/2022] [Accepted: 07/15/2022] [Indexed: 11/16/2022]
Abstract
The consumer market requests infrared (IR) optical components, made of relatively abundant and environmentally friendly materials, to be integrated or attached to smartphones. For this purpose, three new chalcogenides samples, namely Ge23.3Zn30.0Se46.7 (d_GZSe-1), Ge26.7Zn20.0Se53.3 (d_GZSe-2) and Ba4.0Ge12.0Zn17.0Se59.0I8.0 (d_GZSe-3) were obtained by mechanical alloying and processed by spark plasma sintering into dense bulk disks. Obtaining a completely amorphous and homogeneous material proved to be difficult. d_GZSe-2 and d_GZSe-3 are glass-ceramics with the amount of the amorphous phase being 19.7 and 51.4 wt. %, while d_GZSe-1 is fully polycrystalline. Doping with barium and iodine preserves the amorphous phase formed by milling and lowers the sintering temperature from 350 °C to 200 °C. The main crystalline phase in all of the prepared samples is cubic ZnSe or cubic Zn0.5Ge0.25Se, while in d_GZSe-3 the amorphous phase contains GeSe4 clusters. The color of the first two sintered samples is black (the band gap values are 0.42 and 0.79 eV), while d_GZSe-3 is red (Eg is 1.37 eV) and is transparent in IR domain. These results are promising for future research in IR materials and thin films.
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Affiliation(s)
- Alin Velea
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Florinel Sava
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
- Correspondence:
| | - Petre Badica
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Mihail Burdusel
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Claudia Mihai
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Aurelian-Catalin Galca
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Elena Matei
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Angel-Theodor Buruiana
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
- Faculty of Physics, University of Bucharest, Atomistilor 405, 077125 Magurele, Romania
| | - Outman El Khouja
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania; (A.V.); (P.B.); (M.B.); (C.M.); (A.-C.G.); (E.M.); (A.-T.B.); (O.E.K.)
| | - Laurent Calvez
- ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, Université de Rennes, CNRS, F35000 Rennes, France;
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Nedelcu L, Burdusel M, Grigoroscuta MA, Geambasu CD, Enculescu M, Badica P, Banciu MG. Microwave and Terahertz Properties of Spark-Plasma-Sintered Zr 0.8Sn 0.2TiO 4 Ceramics. Materials (Basel) 2022; 15:ma15031258. [PMID: 35161201 PMCID: PMC8838853 DOI: 10.3390/ma15031258] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/31/2022] [Accepted: 02/06/2022] [Indexed: 12/05/2022]
Abstract
Zr0.8Sn0.2TiO3 (ZST) powders synthesized by solid-state reaction were subject to processing by spark plasma sintering (SPS). A single-phase ceramic with a high relative density of 95.7% and 99.6% was obtained for sintering temperatures of 1150 °C and 1200 °C, respectively, and for a dwell time of 3 min. In order to reduce the oxygen vacancies, as-sintered discs were annealed in air at 1000 °C. The dielectric loss of the annealed samples, expressed by the Q × f product, measured in the microwave (MW) domain, varied between 35 THz and 50 THz. The intrinsic losses (Q × f ~ 60 THz) were derived by using terahertz time-domain spectroscopy (THz-TDS).
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Badica P, Batalu ND, Chifiriuc MC, Burdusel M, Grigoroscuta MA, Aldica GV, Pasuk I, Kuncser A, Popa M, Agostino A, Operti L, Padhi SK, Bonino V, Truccato M. Sintered and 3D-Printed Bulks of MgB 2-Based Materials with Antimicrobial Properties. Molecules 2021; 26:molecules26196045. [PMID: 34641589 PMCID: PMC8512174 DOI: 10.3390/molecules26196045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 11/24/2022] Open
Abstract
Pristine high-density bulk disks of MgB2 with added hexagonal BN (10 wt.%) were prepared using spark plasma sintering. The BN-added samples are machinable by chipping them into desired geometries. Complex shapes of different sizes can also be obtained by the 3D printing of polylactic acid filaments embedded with MgB2 powder particles (10 wt.%). Our present work aims to assess antimicrobial activity quantified as viable cells (CFU/mL) vs. time of sintered and 3D-printed materials. In vitro antimicrobial tests were performed against the bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecium DSM 13590, and Enterococcus faecalis ATCC 29212; and the yeast strain Candida parapsilosis ATCC 22019. The antimicrobial effects were found to depend on the tested samples and microbes, with E. faecium being the most resistant and E. coli the most susceptible.
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Affiliation(s)
- Petre Badica
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (I.P.); (A.K.)
- Correspondence: (P.B.); (M.P.); Tel.: +40-21-3690185 (P.B.); +40-21-3690185 (M.P.)
| | - Nicolae Dan Batalu
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- Faculty of Biology and The Research Institute of the University of Bucharest (ICUB), University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania;
| | - Mihail Burdusel
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (I.P.); (A.K.)
| | - Mihai Alexandru Grigoroscuta
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (I.P.); (A.K.)
| | - Gheorghe Virgil Aldica
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (I.P.); (A.K.)
| | - Iuliana Pasuk
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (I.P.); (A.K.)
| | - Andrei Kuncser
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (I.P.); (A.K.)
| | - Marcela Popa
- Faculty of Biology and The Research Institute of the University of Bucharest (ICUB), University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania;
- Correspondence: (P.B.); (M.P.); Tel.: +40-21-3690185 (P.B.); +40-21-3690185 (M.P.)
| | - Angelo Agostino
- Physics and Chemistry Departments, University of Turin, 1-7 Via Pietro Giuria, 10125 Turin, Italy; (A.A.); (L.O.); (S.K.P.); (V.B.); (M.T.)
| | - Lorenza Operti
- Physics and Chemistry Departments, University of Turin, 1-7 Via Pietro Giuria, 10125 Turin, Italy; (A.A.); (L.O.); (S.K.P.); (V.B.); (M.T.)
| | - Santanu Kumar Padhi
- Physics and Chemistry Departments, University of Turin, 1-7 Via Pietro Giuria, 10125 Turin, Italy; (A.A.); (L.O.); (S.K.P.); (V.B.); (M.T.)
| | - Valentina Bonino
- Physics and Chemistry Departments, University of Turin, 1-7 Via Pietro Giuria, 10125 Turin, Italy; (A.A.); (L.O.); (S.K.P.); (V.B.); (M.T.)
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Marco Truccato
- Physics and Chemistry Departments, University of Turin, 1-7 Via Pietro Giuria, 10125 Turin, Italy; (A.A.); (L.O.); (S.K.P.); (V.B.); (M.T.)
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Padhi SK, Baglieri N, Bonino V, Agostino A, Operti L, Batalu ND, Chifiriuc MC, Popa M, Burdusel M, Grigoroscuta MA, Aldica GV, Radu D, Badica P, Truccato M. Antimicrobial Activity of MgB 2 Powders Produced via Reactive Liquid Infiltration Method. Molecules 2021; 26:4966. [PMID: 34443553 PMCID: PMC8399391 DOI: 10.3390/molecules26164966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 12/05/2022] Open
Abstract
We report for the first time on the antimicrobial activity of MgB2 powders produced via the Reactive Liquid Infiltration (RLI) process. Samples with MgB2 wt.% ranging from 2% to 99% were obtained and characterized, observing different levels of grain aggregation and of impurity phases. Their antimicrobial activity was tested against Staphylococcus aureus ATCC BAA 1026, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. A general correlation is observed between the antibacterial activity and the MgB2 wt.%, but the sample microstructure also appears to be very important. RLI-MgB2 powders show better performances compared to commercial powders against microbial strains in the planktonic form, and their activity against biofilms is also very similar.
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Affiliation(s)
- Santanu Kumar Padhi
- Physics and Chemistry Departments, University of Turin, Via P. Giuria 1-7, 10125 Turin, Italy; (S.K.P.); (N.B.); (V.B.); (A.A.); (L.O.)
| | - Nicoletta Baglieri
- Physics and Chemistry Departments, University of Turin, Via P. Giuria 1-7, 10125 Turin, Italy; (S.K.P.); (N.B.); (V.B.); (A.A.); (L.O.)
| | - Valentina Bonino
- Physics and Chemistry Departments, University of Turin, Via P. Giuria 1-7, 10125 Turin, Italy; (S.K.P.); (N.B.); (V.B.); (A.A.); (L.O.)
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Angelo Agostino
- Physics and Chemistry Departments, University of Turin, Via P. Giuria 1-7, 10125 Turin, Italy; (S.K.P.); (N.B.); (V.B.); (A.A.); (L.O.)
| | - Lorenza Operti
- Physics and Chemistry Departments, University of Turin, Via P. Giuria 1-7, 10125 Turin, Italy; (S.K.P.); (N.B.); (V.B.); (A.A.); (L.O.)
| | - Nicolae Dan Batalu
- Metallic Materials Science, Physical Metallurgy Department, Faculty of Materials Science and Engineering, University Politehnica of Bucharest, Splaiul Independentei 313, 060042 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- Faculty of Biology, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Spl. Independentei 91-95, 050095 Bucharest, Romania; (M.C.C.); (M.P.)
- Academy of Romanian Scientists, 050094 Bucharest, Romania
| | - Marcela Popa
- Faculty of Biology, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Spl. Independentei 91-95, 050095 Bucharest, Romania; (M.C.C.); (M.P.)
| | - Mihail Burdusel
- National Institute of Materials Physics, Street Atomistilor 405A, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (D.R.)
| | - Mihai Alexandru Grigoroscuta
- National Institute of Materials Physics, Street Atomistilor 405A, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (D.R.)
| | - Gheorghe Virgil Aldica
- National Institute of Materials Physics, Street Atomistilor 405A, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (D.R.)
| | - Dana Radu
- National Institute of Materials Physics, Street Atomistilor 405A, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (D.R.)
| | - Petre Badica
- National Institute of Materials Physics, Street Atomistilor 405A, 077125 Magurele, Romania; (M.B.); (M.A.G.); (G.V.A.); (D.R.)
| | - Marco Truccato
- Physics and Chemistry Departments, University of Turin, Via P. Giuria 1-7, 10125 Turin, Italy; (S.K.P.); (N.B.); (V.B.); (A.A.); (L.O.)
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Sandu V, Ionescu AM, Aldica G, Grigoroscuta MA, Burdusel M, Badica P. On the pinning force in high density MgB 2 samples. Sci Rep 2021; 11:5951. [PMID: 33723293 PMCID: PMC7961069 DOI: 10.1038/s41598-021-85209-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/22/2021] [Indexed: 11/09/2022] Open
Abstract
An analysis of the field dependence of the pinning force in different, high density sintered samples of MgB2 is presented. The samples were chosen to be representative for pure MgB2, MgB2 with additives, and partially oriented massive samples. In some cases, the curves of pinning force versus magnetic field of the selected samples present peculiar profiles and application of the typical scaling procedures fails. Based on the percolation model, we show that most features of the field dependence of the critical force that generate dissipation comply with the Dew-Hughes scaling law predictions within the grain boundary pinning mechanism if a connecting factor related to the superconducting connection of the grains is used. The field dependence of the connecting function, which is dependent on the superconducting anisotropy, is the main factor that controls the boundary between dissipative and non-dissipative current transport in high magnetic field. Experimental data indicate that the connecting function is also dependent on the particular properties (e.g., the presence of slightly non-stoichiometric phases, defects, homogeneity, and others) of each sample and it has the form of a single or double peaked function in all investigated samples.
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Affiliation(s)
- V Sandu
- National Institute of Materials Physics, Street Atomistilor 405A, 077125, Magurele, Romania
| | - A M Ionescu
- National Institute of Materials Physics, Street Atomistilor 405A, 077125, Magurele, Romania
| | - G Aldica
- National Institute of Materials Physics, Street Atomistilor 405A, 077125, Magurele, Romania
| | - M A Grigoroscuta
- National Institute of Materials Physics, Street Atomistilor 405A, 077125, Magurele, Romania
| | - M Burdusel
- National Institute of Materials Physics, Street Atomistilor 405A, 077125, Magurele, Romania
| | - P Badica
- National Institute of Materials Physics, Street Atomistilor 405A, 077125, Magurele, Romania.
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9
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Miu L, Ionescu AM, Miu D, Burdusel M, Badica P, Batalu D, Crisan A. Second magnetization peak, rhombic-to-square Bragg vortex glass transition, and intersecting magnetic hysteresis curves in overdoped BaFe 2(As 1-xP x) 2 single crystals. Sci Rep 2020; 10:17274. [PMID: 33057042 PMCID: PMC7560746 DOI: 10.1038/s41598-020-74156-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/28/2020] [Indexed: 11/08/2022] Open
Abstract
The second magnetization peak (SMP) in the fourfold symmetric superconducting single crystals (such as iron pnictides and tetragonal cuprates) has been attributed to the rhombic-to-square transition (RST) of the quasi-ordered vortex solid (the Bragg vortex glass, BVG). This represents an alternative to the pinning-induced BVG disordering as the actual SMP mechanism. The analysis of the magnetic response of BaFe2(As1-xPx)2 specimens presented here shows that the SMP is not generated by the RST. However, the latter can affect the pinning-dependent SMP onset field if this is close to the (intrinsic) RST line, through the occurrence of a "shoulder" on the magnetic hysteresis curves m(H), and a maximum in the temperature variation of the DC critical current density. These features disappear in AC conditions, where the vortex system is dynamically ordered in the RST domain, emphasizing the essential role of vortex dislocations for an efficient accommodation of the vortex system to the pinning landscape and the SMP development. The m(H) shoulder is associated with a precipitous pinning-induced proliferation of dislocations at the RST, where the BVG elastic "squash" modulus softens. The DC magnetization relaxation indicates that the pinning-induced vortex system disordering continues above the RST domain, as the basic SMP mechanism.
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Affiliation(s)
- L Miu
- National Institute of Materials Physics, 077125, Magurele, Romania
| | - A M Ionescu
- National Institute of Materials Physics, 077125, Magurele, Romania
| | - D Miu
- National Institute of Laser, Plasma, and Radiation Physics, 077125, Magurele, Romania
| | - M Burdusel
- National Institute of Materials Physics, 077125, Magurele, Romania
| | - P Badica
- National Institute of Materials Physics, 077125, Magurele, Romania
| | - D Batalu
- SC Fileo Buildup SRL, 060816, Bucharest, Romania
| | - A Crisan
- National Institute of Materials Physics, 077125, Magurele, Romania.
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10
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Li CJ, Xue HX, Qu GL, Shen SC, Hong YP, Wang XX, Liu MR, Jiang WM, Badica P, He L, Dou RF, Xiong CM, Lü WM, Nie JC. Influence of In-Gap States on the Formation of Two-Dimensional Election Gas at ABO 3/SrTiO 3 Interfaces. Sci Rep 2018; 8:195. [PMID: 29317754 PMCID: PMC5760580 DOI: 10.1038/s41598-017-18583-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/13/2017] [Indexed: 12/01/2022] Open
Abstract
We explored in-gap states (IGSs) in perovskite oxide heterojunction films. We report that IGSs in these films play a crucial role in determining the formation and properties of interfacial two-dimensional electron gas (2DEG). We report that electron trapping by IGSs opposes charge transfer from the film to the interface. The IGS in films yielded insulating interfaces with polar discontinuity and explained low interface carrier density of conducting interfaces. An ion trapping model was proposed to explain the physics of the IGSs and some experimental findings, such as the unexpected formation of 2DEG at the initially insulating LaCrO3/SrTiO3 interface and the influence of substitution layers on 2DEG.
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Affiliation(s)
- Cheng-Jian Li
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Hong-Xia Xue
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Guo-Liang Qu
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Sheng-Chun Shen
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Yan-Peng Hong
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Xin-Xin Wang
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Ming-Rui Liu
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Wei-Min Jiang
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Petre Badica
- National Institute of Materials Physics, Atomistilor 405A, Magurele, Ilfov, 077125, Romania
| | - Lin He
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Rui-Fen Dou
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Chang-Min Xiong
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Wei-Ming Lü
- Condensed Matter Science and Technology Institute, Harbin Institute of Technology, Harbin, 150001, China
| | - Jia-Cai Nie
- Department of Physics, Beijing Normal University, Beijing, 100875, China.
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11
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Florea NM, Lungu A, Balanuca B, Badica P, Craciun L, Damian CM, Enculescu M, Ionescu C, Tihan G, Iovu H. Effect of polyhedral oligomeric silsesquioxane nanoreinforcement on the properties of epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) nanocomposites. HIGH PERFORM POLYM 2016. [DOI: 10.1177/0954008315595447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article reports the synthesis and characterization of several types of organic–inorganic nanocomposites based on epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) reinforced with 2, 5, or 10 wt% polyhedral oligomeric silsesquioxanes (POSS) bearing one glycidyl (1GE-POSS) or eight glycidyl(8GE-POSS) groups. The morphological features of the studied samples were established through atomic force microscopy, contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy, and it was demonstrated that 8GE-POSS is well dispersed within the polymer matrix, while 1GE-POSS exhibits a high tendency to form aggregates. Differential scanning calorimetry (DSC) and Fourier transform infrared resonance (FTIR) measurements are used to follow the curing behavior and to study the polymerization kinetics of epoxy groups. As evidenced by DSC and FTIR results, the inclusion of 8GE-POSS within the polymer matrix leads to a lower epoxy polymerization rate of the resulted nanocomposites than those reinforced with 1GE-POSS. The dynamic mechanical analysis results revealed that the thermomechanical properties are gradually improved with increasing of 8GE-POSS content due to the higher cross-linking density.
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Affiliation(s)
- Nicoleta M Florea
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
- Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Brindusa Balanuca
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Petre Badica
- National Institute of Materials Physics, Magurele, Romania
| | - Liviu Craciun
- Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania
| | - Celina M Damian
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | | | - Cristina Ionescu
- Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania
| | - Gratiela Tihan
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
- Academy of Romanian Scientists, Bucharest, Romania
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12
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Batalu ND, Semenescu A, Mates IM, Negoita OD, Purcarea VL, Badica P. Computer assisted design and finite element analysis of contact lenses. Rom J Ophthalmol 2016; 60:132-137. [PMID: 29450337 PMCID: PMC5720124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 06/08/2023] Open
Abstract
Contact lenses are an attractive alternative for vision corrections. Their improvement can be achieved by optimizing the geometry, use of new materials, and application of high precision processing technologies. The optimized design can be obtained by computer-aided design, considering the principles of geometrical optics. Inventor Professional and other similar advanced 3D CAD software allows complex approaches, selection of suitable materials with better mechanical/ optical properties. This is useful for the preparation of the virtual design for 3D printing or CNC fabrication. A finite element analysis is also of interest for testing the best design/ material choice. In this paper, the finite element analysis for a tri-curve contact lens was applied. The selected materials were PMMA and polycarbonate. The applied compressive loads were in the range from 10 to 100MPa. Our results showed that the best scenario was for the polycarbonate, but PMMA also had a high safety factor. The maximum compression load with a reasonable safety factor (of 7-9 depending on materials) was 12MPa.
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Affiliation(s)
| | | | - Ileana Mariana Mates
- "Dr. Carol Davila" Central Military Emergency University Hospital, Bucharest, Romania
| | | | | | - Petre Badica
- National Institute of Materials Physics, Magurele, Ilfov
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13
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Cojocaru M, Velcea F, Badica P. Highly alloyed steel matrix for tools fabricated by powder metallurgy. Surf Engin Appl Electrochem 2015. [DOI: 10.3103/s1068375515030059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Batalu D, Stanciuc AM, Moldovan L, Aldica G, Badica P. Evaluation of pristine and Eu ₂O₃-added MgB ₂ ceramics for medical applications: hardness, corrosion resistance, cytotoxicity and antibacterial activity. Mater Sci Eng C Mater Biol Appl 2014; 42:350-61. [PMID: 25063128 DOI: 10.1016/j.msec.2014.05.046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/05/2014] [Accepted: 05/18/2014] [Indexed: 11/19/2022]
Abstract
Nano- or micropowders of Eu2O3 were added to MgB2, resulting in a composition of (MgB2)0.975(EuO1.5)0.025. Pristine and doped samples were prepared using spark plasma sintering and tested for (i) Vickers hardness, (ii) pH evolution in phosphate-buffered saline solution, (iii) corrosion resistance (Tafel polarization curves), (iv) cytotoxicity (in vitro tests), and (v) antibacterial activity. Eu2O3 addition influenced the investigated properties. Solutions of MgB2-based samples show a relatively high saturation pH of 8.5. This value is lower than that of solutions incubated with Mg or other Mg-based biodegradable alloys reported in the literature. MgB2-based samples have lower electro-corrosion rates than Mg. Their Vickers hardness is 6.8-10.2GPa, and these values are higher than those of biodegradable Mg-based alloys. MgB2 has low in vitro biocompatibility, good antibacterial activity against Escherichia coli, and mild activity against Staphylococcus aureus. Our results suggest that MgB2-based materials deserve attention in biomedical applications, such as implants or sterile medical instruments.
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Affiliation(s)
- Dan Batalu
- University Politehnica of Bucharest, Splaiul Independentei 313, 060042 Bucharest, Romania.
| | - Ana Maria Stanciuc
- National Institute for Biological Sciences, Splaiul Independentei 296, 060031 Bucharest, Romania
| | - Lucia Moldovan
- National Institute for Biological Sciences, Splaiul Independentei 296, 060031 Bucharest, Romania
| | - Gheorghe Aldica
- National Institute of Materials Physics, Atomistilor 105 bis, 077125 Magurele, Romania
| | - Petre Badica
- National Institute of Materials Physics, Atomistilor 105 bis, 077125 Magurele, Romania.
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15
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Plapcianu C, Agostino A, Badica P, Aldica GV, Bonometti E, Ieluzzi G, Popa S, Truccato M, Cagliero S, Sakka Y, Vasylkiv O, Vidu R. Microwave Synthesis of Fullerene-Doped MgB2. Ind Eng Chem Res 2012. [DOI: 10.1021/ie3005429] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Plapcianu
- CNISM and NIS Center of Excellence, Department of Physics, University of Torino, Via P. Giuria 1, I-10125 Torino,
Italy
- NIS Center of Excellence,
Department of Chemistry, University of Torino, Via P. Giuria 7, I-10125 Torino, Italy
- National Institute of Materials Physics, 105 bis Atomistilor strasse, P.O. Box MG-7, 077125 Magurele, Ilfov,
Romania
| | - A. Agostino
- NIS Center of Excellence,
Department of Chemistry, University of Torino, Via P. Giuria 7, I-10125 Torino, Italy
| | - P. Badica
- National Institute of Materials Physics, 105 bis Atomistilor strasse, P.O. Box MG-7, 077125 Magurele, Ilfov,
Romania
| | - G. V. Aldica
- CNISM and NIS Center of Excellence, Department of Physics, University of Torino, Via P. Giuria 1, I-10125 Torino,
Italy
- National Institute of Materials Physics, 105 bis Atomistilor strasse, P.O. Box MG-7, 077125 Magurele, Ilfov,
Romania
| | - E. Bonometti
- NIS Center of Excellence,
Department of Chemistry, University of Torino, Via P. Giuria 7, I-10125 Torino, Italy
| | - G. Ieluzzi
- NIS Center of Excellence,
Department of Chemistry, University of Torino, Via P. Giuria 7, I-10125 Torino, Italy
| | - S. Popa
- National Institute of Materials Physics, 105 bis Atomistilor strasse, P.O. Box MG-7, 077125 Magurele, Ilfov,
Romania
| | - M. Truccato
- CNISM and NIS Center of Excellence, Department of Physics, University of Torino, Via P. Giuria 1, I-10125 Torino,
Italy
| | - S. Cagliero
- CNISM and NIS Center of Excellence, Department of Physics, University of Torino, Via P. Giuria 1, I-10125 Torino,
Italy
- NIS Center of Excellence,
Department of Chemistry, University of Torino, Via P. Giuria 7, I-10125 Torino, Italy
| | - Y. Sakka
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba
305-0051, Japan
| | - O. Vasylkiv
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba
305-0051, Japan
| | - R. Vidu
- University of California, 3123 Bainer Hall, Davis,
California
95616, United States
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16
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Vasylkiv O, Borodianska H, Badica P, Grasso S, Sakka Y, Tok A, Su LT, Bosman M, Ma J. High hardness BaCb-(BxOy/BN) composites with 3D mesh-like fine grain-boundary structure by reactive spark plasma sintering. J Nanosci Nanotechnol 2012; 12:959-965. [PMID: 22629879 DOI: 10.1166/jnn.2012.5875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Boron carbide B4C powders were subject to reactive spark plasma sintering (also known as field assisted sintering, pulsed current sintering or plasma assisted sintering) under nitrogen atmosphere. For an optimum hexagonal BN (h-BN) content estimated from X-ray diffraction measurements at approximately 0.4 wt%, the as-prepared BaCb-(BxOy/BN) ceramic shows values of Berkovich and Vickers hardness of 56.7 +/- 3.1 GPa and 39.3 +/- 7.6 GPa, respectively. These values are higher than for the vacuum SPS processed B4C pristine sample and the h-BN -mechanically-added samples. XRD and electronic microscopy data suggest that in the samples produced by reactive SPS in N2 atmosphere, and containing an estimated amount of 0.3-1.5% h-BN, the crystallite size of the boron carbide grains is decreasing with the increasing amount of N2, while for the newly formed lamellar h-BN the crystallite size is almost constant (approximately 30-50 nm). BN is located at the grain boundaries between the boron carbide grains and it is wrapped and intercalated by a thin layer of boron oxide. BxOy/BN forms a fine and continuous 3D mesh-like structure that is a possible reason for good mechanical properties.
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Affiliation(s)
- Oleg Vasylkiv
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
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17
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Badica P, Crisan A, Aldica G, Endo K, Borodianska H, Togano K, Awaji S, Watanabe K, Sakka Y, Vasylkiv O. 'Beautiful' unconventional synthesis and processing technologies of superconductors and some other materials. Sci Technol Adv Mater 2011; 12:013001. [PMID: 27877374 PMCID: PMC5090396 DOI: 10.1088/1468-6996/12/1/11660943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 02/16/2011] [Accepted: 12/15/2010] [Indexed: 06/06/2023]
Abstract
Superconducting materials have contributed significantly to the development of modern materials science and engineering. Specific technological solutions for their synthesis and processing helped in understanding the principles and approaches to the design, fabrication and application of many other materials. In this review, we explore the bidirectional relationship between the general and particular synthesis concepts. The analysis is mostly based on our studies where some unconventional technologies were applied to different superconductors and some other materials. These technologies include spray-frozen freeze-drying, fast pyrolysis, field-assisted sintering (or spark plasma sintering), nanoblasting, processing in high magnetic fields, methods of control of supersaturation and migration during film growth, and mechanical treatments of composite wires. The analysis provides future research directions and some key elements to define the concept of 'beautiful' technology in materials science. It also reconfirms the key position and importance of superconductors in the development of new materials and unconventional synthesis approaches.
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Affiliation(s)
- Petre Badica
- National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125, Romania
| | - Adrian Crisan
- National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125, Romania
- School of Metallurgy and Materials, Birmingham University, Birmingham B15 2TT, UK
| | - Gheorghe Aldica
- National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125, Romania
| | - Kazuhiro Endo
- Research Laboratory for Integrated Technological Systems, Kanazawa Institute of Technology (KIT), 3-1 Yatsukaho, Hakusan, Ishikawa 924-0838, Japan
| | - Hanna Borodianska
- Institute for Materials Science, NASU, 3, Krzhizhanivsky, Kiev 03680, Ukraine
| | - Kazumasa Togano
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Satoshi Awaji
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577, Japan
| | - Kazuo Watanabe
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577, Japan
| | - Yoshio Sakka
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Oleg Vasylkiv
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
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18
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Vasylkiv O, Borodianska H, Badica P, Zhen Y, Tok A. Nanoblast synthesis and consolidation of (La0.8Sr0.2)(Ga0.9Mg0.1)O(3-delta) under Spark plasma sintering conditions. J Nanosci Nanotechnol 2009; 9:141-149. [PMID: 19441288 DOI: 10.1166/jnn.2009.j008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Four-cation nanograined strontium and magnesium doped lanthanum gallate (La0.8Sr0.2) (Ga0.9Mg0.1)O(3-delta) (LSGM) and its composite with 2 wt% of ceria (LSGM-Ce) were prepared. Morphologically homogeneous nanoreactors, i.e., complex intermediate metastable aggregates of desired composition were assembled by spray atomization technique, and subsequently loaded with nanoparticles of highly energetic C3H6N6O6. Rapid nanoblast calcination technique was applied and the final composition was synthesized within the preliminary localized volumes of each single nanoreactor on the first step of spark plasma treatment. Subsequent SPS consolidations of nanostructured extremely active LSGM and LSGM-Ce powders were achieved by rapid treatment under pressures of 90-110 MPa. This technique provided the heredity of the final structure of nanosize multimetal oxide, allowed the prevention of the uncontrolled agglomeration during multicomponent aggregates assembling, subsequent nanoblast calcination, and final ultra-rapid low-temperature SPS consolidation of nanostructured ceramics. LaSrGaMgCeO(3-delta) nanocrystalline powder consisting of approximately 11 nm crystallites was consolidated to LSGM-Ce nanoceramic with average grain size of approximately 14 nm by low-temperature SPS at 1250 degrees C. Our preliminary results indicate that nanostructured samples of (La0.8Sr0.2)(Ga0.9Mg0.1)O(3-delta) with 2 wt% of ceria composed of approximataley 14 nm grains can exhibit giant magnetoresistive effect in contrast to the usual paramagnetic properties measured on the samples with larger grain size.
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Affiliation(s)
- Oleg Vasylkiv
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0051, Japan
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19
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Endo K, Badica P. Growth control of perovskite-related oxide thin films. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308082056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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20
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Shimojima T, Ishizaka K, Tsuda S, Kiss T, Yokoya T, Chainani A, Shin S, Badica P, Yamada K, Togano K. Angle-resolved photoemission study of the cobalt oxide superconductor Na(x)CoO(2) x yH(2)O: observation of the Fermi surface. Phys Rev Lett 2006; 97:267003. [PMID: 17280457 DOI: 10.1103/physrevlett.97.267003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Indexed: 05/13/2023]
Abstract
The cobalt oxide superconductor Na(x)CoO(2) x yH(2)O is studied by angle-resolved photoemission spectroscopy. We report the Fermi surface (FS) topology and electronic structure near the Fermi level (E(F)) in the normal state of Na(x)CoO(2) x yH(2)O. Our result indicates the presence of the hexagonal FS centered at the Gamma point, while the small pocket FSs along Gamma-K direction are absent, similar to Na(x)CoO(2). The top of the e(g)(') band, which is expected in band calculations to form the small pocket FSs, extends to within approximately 30 meV below E(F), closer to E(F) than in Na(x)CoO(2). We discuss its possible role in superconductivity, comparing with other experimental and theoretical results.
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Affiliation(s)
- T Shimojima
- Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
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21
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Yuan HQ, Agterberg DF, Hayashi N, Badica P, Vandervelde D, Togano K, Sigrist M, Salamon MB. S-wave spin-triplet order in superconductors without inversion symmetry: Li2Pd3B and Li2Pt3B. Phys Rev Lett 2006; 97:017006. [PMID: 16907402 DOI: 10.1103/physrevlett.97.017006] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Indexed: 05/11/2023]
Abstract
We investigate the order parameter of noncentrosymmetric superconductors Li2Pd3B and Li2Pt3B via the behavior of the penetration depth lambda(T). The low-temperature penetration depth shows BCS-like behavior in Li2Pd3B, while in Li2Pt3B it follows a linear temperature dependence. We propose that broken inversion symmetry and the accompanying antisymmetric spin-orbit coupling, which admix spin-singlet and spin-triplet pairing, are responsible for this behavior. The triplet contribution is weak in Li2Pd3B, leading to a wholly open but anisotropic gap. The significantly larger spin-orbit coupling in Li2Pt3B allows the spin-triplet component to be larger in Li2Pt3B, producing line nodes in the energy gap as evidenced by the linear temperature dependence of lambda(T). The experimental data are in quantitative agreement with theory.
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Affiliation(s)
- H Q Yuan
- Department of Physics, University of Illinois at Urbana and Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA.
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Togano K, Badica P, Nakamori Y, Orimo S, Takeya H, Hirata K. Superconductivity in the metal rich Li-Pd-B ternary boride. Phys Rev Lett 2004; 93:247004. [PMID: 15697851 DOI: 10.1103/physrevlett.93.247004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Indexed: 05/24/2023]
Abstract
Superconductivity at about 8 K was observed in the metal-rich Li-Pd-B ternary system. Structural, microstructural, electrical, and magnetic investigations for various compositions proved that the Li2Pd3B compound, which has an antiperovskite cubic structure composed of distorted Pd6B octahedrons, is responsible for the superconductivity. This is the first observation of superconductivity in metal-rich ternary borides containing alkaline metal and Pd as a late transition metal. The compound prepared by arc melting has a high density and is relatively stable in the air. The upper critical fields H(c2)(0) estimated by linear extrapolation and the Werthamer-Helfand-Hohenberg theory are 6.2 and 4.8 T, respectively.
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Affiliation(s)
- K Togano
- Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan.
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