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Castañeda BN, Calderon HA, Martinez H. Electron Microscopy of Volcanic Rocks: from Optical to SEM analysis of Volcanic Rocks and its Mineralogical Constitution. Microsc Microanal 2023; 29:2028-2031. [PMID: 37612955 DOI: 10.1093/micmic/ozad067.1049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
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Calderon HA, Fan Z, Samprash R, Robles Hernandez FC. Electron Microscopy of Carbon Soots for Battery Applications. Microsc Microanal 2023; 29:119-120. [PMID: 37613361 DOI: 10.1093/micmic/ozad067.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- H A Calderon
- Instituto Politécnico Nacional, Dept. Física ESFM-IPN, Zacatenco CDMX, México
| | - Z Fan
- Department of Mechanical Engineering Technology, University of Houston, Houston, TX, United States
| | - R Samprash
- Department of Mechanical Engineering Technology, University of Houston, Houston, TX, United States
| | - F C Robles Hernandez
- Department of Mechanical Engineering Technology, University of Houston, Houston, TX, United States
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Hadjiev VG, Wang C, Wang Y, Su X, Calderon HA, Robles Hernandez F, Wang ZM, Bao JM. Phonon fingerprints of CsPb 2Br 5. J Phys Condens Matter 2018; 30:405703. [PMID: 30179162 DOI: 10.1088/1361-648x/aadeb4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
CsPb2Br5 is a stable, water-resistant, material derived from CsPbBr3 perovskite and featuring two-dimensional Pb-Br framework separated by Cs layers. Both compounds can coexist at nanolength scale, which often produces conflicting optical spectroscopy results. We present a complete set of polarized Raman spectra of nonluminescent CsPb2Br5 single crystals that reveals the symmetry and frequency of nondegenerate Raman active phonons accessible from the basal (0 0 1) plane. The experimental results are in good agreement with density functional perturbation theory simulations, which suggests that the calculated frequencies of yet unobserved double degenerate Raman and infrared phonons are also reliable. Unlike CsPbBr3, the lattice dynamics of CsPb2Br5 is stable as evidenced by the calculated phonon dispersion. The sharp Raman lines and lack of a dynamic-disorder-induced central peak in the spectra at room temperature indicate that the coupling of Cs anharmonic motion to Br atoms, known to cause the dynamic disorder in CsPbBr3, is absent in CsPb2Br5.
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Affiliation(s)
- V G Hadjiev
- Texas Center for Superconductivity, University of Houston, Houston, TX 77204, United States of America. Department of Mechanical Engineering, University of Houston, Houston, TX 77204, United States of America
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Kisielowski C, Calderon HA, Chen FR, Helveg S, Jinschek JR, Specht P, Van Dyck D. Comment on, "On the influence of the electron dose-rate on the HRTEM image contrast", by Juri Barthel, Markus Lentzen, Andreas Thust, ULTRAM12246 (2016), http://dx.doi.org/10.1016/j.ultramic.2016.11.016. Ultramicroscopy 2017; 179:108-112. [PMID: 28412016 DOI: 10.1016/j.ultramic.2017.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/04/2017] [Indexed: 11/17/2022]
Affiliation(s)
- C Kisielowski
- Lawrence Berkeley National Laboratory, The Molecular Foundry, One Cyclotron Road, Berkeley, CA 94720, USA.
| | - H A Calderon
- Departamento de Física, Instituto Politecnico Nacional ESFM, UPALM-Zacatenco Ed. 9, México CDMX, Mexico
| | - F R Chen
- Department of Engineering and System Science, National Tsing-Hua University, 101 Kuang-Fu Road, Hsin Chu 300, Taiwan
| | - S Helveg
- Haldor Topsoe A/S, Haldor Topsøes Allé 1, Kgs. Lyngby, DK-2800 Denmark
| | - J R Jinschek
- Department of Materials Science and Engineering, Center for Electron Microscopy and Analysis (CEMAS), The Ohio State University, 1305 Kinnear Rd, Columbus, OH 43212, USA
| | - P Specht
- Department of Materials Science & Engineering, University of California-Berkeley, Berkeley, CA 94720, USA
| | - D Van Dyck
- EMAT, Department of Physics, University of Antwerp, Antwerpen 2020, Belgium
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Calderon HA, Okonkwo A, Estrada-Guel I, Hadjiev VG, Alvarez-Ramírez F, Robles Hernández FC. HRTEM low dose: the unfold of the morphed graphene, from amorphous carbon to morphed graphenes. ACTA ACUST UNITED AC 2016; 2:10. [PMID: 27617185 PMCID: PMC4993800 DOI: 10.1186/s40679-016-0024-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [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: 03/16/2016] [Accepted: 08/05/2016] [Indexed: 11/10/2022]
Abstract
We present experimental evidence under low-dose conditions transmission electron microscopy for the unfolding of the evolving changes in carbon soot during mechanical milling. The milled soot shows evolving changes as a function of the milling severity or time. Those changes are responsible for the transformation from amorphous carbon to graphenes, graphitic carbon, and highly ordered structures such as morphed graphenes, namely Rh6 and Rh6-II. The morphed graphenes are corrugated layers of carbon with cross-linked covalently nature and sp2- or sp3-type allotropes. Electron microscopy and numerical simulations are excellent complementary tools to identify those phases. Furthermore, the TEAM 05 microscope is an outstanding tool to resolve the microstructure and prevent any damage to the sample. Other characterization techniques such as XRD, Raman, and XPS fade to convey a true identification of those phases because the samples are usually blends or mixes of the mentioned phases.
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Affiliation(s)
- H A Calderon
- Departamento de Física, ESFM-IPN, Ed. 9 Instituto Politécnico Nacional UPALM, 07738 Mexico D.F., Mexico
| | - A Okonkwo
- Department of Mechanical Engineering Technology, University of Houston, Houston, TX 77204-4020 USA
| | - I Estrada-Guel
- Department of Mechanical Engineering Technology, University of Houston, Houston, TX 77204-4020 USA ; Centro de Investigación en Materiales Avanzados, CIMAV, Miguel de Cervantes 120, 31109 Chihuahua, Chih. Mexico
| | - V G Hadjiev
- Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 USA
| | - F Alvarez-Ramírez
- Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, Mexico, DF 07730 Mexico
| | - F C Robles Hernández
- Department of Mechanical Engineering Technology, University of Houston, Houston, TX 77204-4020 USA ; Center for Advanced Materials, University of Houston, Houston, TX 77204 USA
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Ramos-Sanchez G, Praserthdam S, Godinez-Salomon F, Barker C, Moerbe M, Calderon HA, Lartundo LA, Leyva MA, Solorza-Feria O, Balbuena PB. Challenges of modelling real nanoparticles: Ni@Pt electrocatalysts for the oxygen reduction reaction. Phys Chem Chem Phys 2015; 17:28286-97. [DOI: 10.1039/c5cp00503e] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Core–shell nanoparticle properties strongly dependent on cluster size and composition.
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Affiliation(s)
- G. Ramos-Sanchez
- Department of Chemical Engineering
- Texas A&M University
- College Station
- USA
- Departamento de Química
| | - S. Praserthdam
- Department of Chemical Engineering
- Texas A&M University
- College Station
- USA
| | - F. Godinez-Salomon
- Departamento de Química
- Centro de Investigación y de Estudios Avanzados del IPN
- México D.F
- Mexico
| | - C. Barker
- Department of Chemical Engineering
- Texas A&M University
- College Station
- USA
| | - M. Moerbe
- Department of Chemical Engineering
- Texas A&M University
- College Station
- USA
| | - H. A. Calderon
- Depto. de Ciencia de Materiales
- ESFM-IPN
- Zacatenco México-D.F. CP. 07738
- Mexico
| | - L. A. Lartundo
- Centro de Nanociencias y Micro y Nanotecnologías-IPN
- UPALM
- Zacatenco México-D.F. CP. 07738
- Mexico
| | - M. A. Leyva
- Departamento de Química
- Centro de Investigación y de Estudios Avanzados del IPN
- México D.F
- Mexico
| | - O. Solorza-Feria
- Departamento de Química
- Centro de Investigación y de Estudios Avanzados del IPN
- México D.F
- Mexico
| | - P. B. Balbuena
- Department of Chemical Engineering
- Texas A&M University
- College Station
- USA
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Calderon HA, Kisielowski C, Specht P, Barton B, Godinez-Salomon F, Solorza-Feria O. Maintaining the genuine structure of 2D materials and catalytic nanoparticles at atomic resolution. Micron 2014; 68:164-175. [PMID: 25240633 DOI: 10.1016/j.micron.2014.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [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: 04/18/2014] [Revised: 08/13/2014] [Accepted: 08/19/2014] [Indexed: 11/16/2022]
Abstract
The recent development of atomic resolution, low dose-rate electron microscopy allows investigating 2D materials as well as catalytic nano particles without compromising their structural integrity. For graphene and a variety of nanoparticle compositions, it is shown that a critical dose rate exists of <100 e(-)/Å(2) s at 80 keV of electron acceleration that allows maintaining the genuine object structures including their surfaces and edges even if particles are only 3 nm large or smaller. Moreover, it is demonstrated that electron beam-induced phonon excitation from outside the field of view contributes to a contrast degradation in recorded images. These degradation effects can be eliminated by delivering electrons onto the imaged area, only, by using a Nilsonian illumination scheme in combination with a suitable aperture at the electron gun/monochromator assembly.
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Affiliation(s)
- H A Calderon
- Departamento de Física, ESFM-IPN, Ed. 9, UPALM-Zacatenco, México, D.F., Mexico.
| | - C Kisielowski
- National Center for Electron Microscopy and Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, One Cyclotron Rd, Berkeley, CA 94720, USA
| | - P Specht
- Dept. Mats. Sci. Eng., UCB, Berkeley, CA 94720, USA
| | - B Barton
- National Center for Electron Microscopy and Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, One Cyclotron Rd, Berkeley, CA 94720, USA
| | - F Godinez-Salomon
- Depto. Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CINVESTAV-IPN, 07360 México, D.F., Mexico
| | - O Solorza-Feria
- Depto. Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CINVESTAV-IPN, 07360 México, D.F., Mexico
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Calderon HA, Caba-As-Moreno JG, Cruz JJ, Pedersen JS. Analysis of anisotropic SANS patterns obtained from Ni–Al–Mo alloys with bimodal particle size distributions. Acta Crystallogr A 1996. [DOI: 10.1107/s0108767396097772] [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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