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Jia Q, Zou G, Wang W, Ren H, Zhang H, Deng Z, Feng B, Liu L. Sintering Mechanism of a Supersaturated Ag-Cu Nanoalloy Film for Power Electronic Packaging. ACS APPLIED MATERIALS & INTERFACES 2020; 12:16743-16752. [PMID: 32174102 DOI: 10.1021/acsami.9b20731] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ag-Cu bimetallic nanoparticles, combining the advantages of both Ag and Cu, are a promising material for power electronic packaging. In this work, a supersaturated Ag-7.3 wt % Cu alloy nanoparticle film was developed by using pulsed laser deposition. Unlike Cu nanoparticles, the supersaturated Ag-Cu alloy nanoparticles can conduct bonding in air without the assistance of a reduction agent. The shear strength was >20 MPa when the bonding temperature reached 300 °C, which was above the die shear standard (MIL-STD-883 K, 7.8 MPa) and compatible with the typical die attach process. The Cu separating behavior was accompanied by the bonding process at 250-400 °C, which was discussed systematically. Neck formation was delayed to about 250 °C because of the hindering effect of the thin oxide shell of the Ag-Cu alloy. The necking networks provide volume diffusion paths despite the growth of surface oxide, resulting in compact densification. The bondline under the SiC die consisted of a porous Ag-Cu alloy matrix with a dispersed secondary phase of Cu2O/CuO, which is supposed to have improved electrochemical migration resistance.
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Affiliation(s)
- Qiang Jia
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Guisheng Zou
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Wengan Wang
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Hui Ren
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Hongqiang Zhang
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China
| | - Zhongyang Deng
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Bin Feng
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Lei Liu
- Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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Bag S, Baksi A, Wang D, Kruk R, Benel C, Chellali MR, Hahn H. Combination of pulsed laser ablation and inert gas condensation for the synthesis of nanostructured nanocrystalline, amorphous and composite materials. NANOSCALE ADVANCES 2019; 1:4513-4521. [PMID: 36134399 PMCID: PMC9418463 DOI: 10.1039/c9na00533a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 10/17/2019] [Indexed: 05/24/2023]
Abstract
A new instrument combining pulsed laser ablation and inert gas condensation for the production of nanopowders is presented. It is shown that various nanostructured materials, such as regular metallic, semiconducting, insulating materials, complex high entropy alloys, amorphous alloys, composites and oxides can be synthesized. The unique variability of the experimental set-up is possible due to the reproducible control of laser power (pulse energy and repetition rate), laser ablation pattern on the target, and experimental conditions during the inert gas condensation, all of which can be controlled and optimized independently. Microstructure analysis of the as-prepared composite and amorphous Ni60Nb40 nanopowders establishes the instrument's ability for the synthesis of materials with unique compositions and atomic structure. It is further shown that small variations of the synthesis parameters can influence materials properties of the final product, in terms of particle size, composition and properties. As an example, the laser power has been used to control the magnetic properties of amorphous Ni60Nb40 nanopowders. A few selected examples of the manifold possibilities of the new synthesis apparatus are presented in this report together with detailed structural characterization of the produced nanopowders.
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Affiliation(s)
- Soumabha Bag
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
| | - Ananya Baksi
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
| | - Di Wang
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
- Karlsruhe Nano Micro Facility, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
| | - Robert Kruk
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
| | - Cahit Benel
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
| | - Mohammed Reda Chellali
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
| | - Horst Hahn
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76344 Eggenstein-Leopoldshafen Germany
- Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology Nanjing China
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Chattopadhyay S, Kelly SD, Shibata T, Balasubramanian M, Srinivasan SG, Du J, Banerjee R, Ayyub P. Local structure, composition, and crystallization mechanism of a model two-phase "composite nanoglass". J Chem Phys 2016; 144:064503. [PMID: 26874493 DOI: 10.1063/1.4941334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report a detailed study of the local composition and structure of a model, bi-phasic nanoglass with nominal stoichiometry Cu55Nb45. Three dimensional atom probe data suggest a nanoscale-phase-separated glassy structure having well defined Cu-rich and Nb-rich regions with a characteristic length scale of ≈ 3 nm. However, extended x-ray absorption fine structure analysis indicates subtle differences in the local environments of Cu and Nb. While the Cu atoms displayed a strong tendency to cluster and negligible structural order beyond the first coordination shell, the Nb atoms had a larger fraction of unlike neighbors (higher chemical order) and a distinctly better-ordered structural environment (higher topological order). This provides the first experimental indication that metallic glass formation may occur due to frustration arising from the competition between chemical ordering and clustering. These observations are complemented by classical as well as ab initio molecular dynamics simulations. Our study indicates that these nanoscale phase-separated glasses are quite distinct from the single phase nanoglasses (studied by Gleiter and others) in the following three respects: (i) they contain at least two structurally and compositionally distinct, nanodispersed, glassy phases, (ii) these phases are separated by comparatively sharp inter-phase boundaries, and (iii) thermally induced crystallization occurs via a complex, multi-step mechanism. Such materials, therefore, appear to constitute a new class of disordered systems that may be called a composite nanoglass.
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Affiliation(s)
- Soma Chattopadhyay
- CSRRI-IIT, MRCAT, Sector 10, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S D Kelly
- EXAFS Analysis, Bolingbrook, Illinois 60440, USA
| | - Tomohiro Shibata
- CSRRI-IIT, MRCAT, Sector 10, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Balasubramanian
- Sector 20 XOR, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S G Srinivasan
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203-5017, USA
| | - Jincheng Du
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203-5017, USA
| | - Rajarshi Banerjee
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203-5017, USA
| | - Pushan Ayyub
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005, India
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Chen N, Wang D, Feng T, Kruk R, Yao KF, Louzguine-Luzgin DV, Hahn H, Gleiter H. A nanoglass alloying immiscible Fe and Cu at the nanoscale. NANOSCALE 2015; 7:6607-6611. [PMID: 25792519 DOI: 10.1039/c5nr01406a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Synthesized from ultrafine particles with a bottom-up approach, nanoglasses are of particular importance in pursuing unique properties. Here, we design a metallic nanoglass alloy from two components of ∼Cu64Sc36 and ∼Fe90Sc10 nanoglasses. With nanoalloying mutually immiscible Fe and Cu, the properties of the nanoglass alloys can be tuned by varying the proportions of the ∼Fe90Sc10 component. This offers opportunity to create novel metallic glass nanocomposites and sheds light on building a structure-property correlation for the nanoglass alloys.
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Affiliation(s)
- Na Chen
- Institute for Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe 76021, Germany
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Ketov SV, Shi X, Xie G, Kumashiro R, Churyumov AY, Bazlov AI, Chen N, Ishikawa Y, Asao N, Wu H, Louzguine-Luzgin DV. Nanostructured Zr-Pd metallic glass thin film for biochemical applications. Sci Rep 2015; 5:7799. [PMID: 25589472 PMCID: PMC5155374 DOI: 10.1038/srep07799] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 12/18/2014] [Indexed: 11/24/2022] Open
Abstract
Zr-Pd metallic glassy thin films with a hierarchical nano-scale structure, produced by magnetron sputtering of the Zr and Pd powder mixture, demonstrate a unique combination of physical and biochemical properties. Thermal stability of the nano-structured glassy samples, their resistance to oxidation in dry air and phase transformation behavior are discussed in the present work. These binary alloy samples also show exceptionally high corrosion resistance and spontaneous passivation in a simulated body fluid. Experiments on the catalytic activity and biocompatibility of this nanostructured metallic glass indicate that this is a very suitable material for biochemical applications. Compared to the multicomponent alloys studied earlier this binary alloy has much simpler chemical composition, which makes preparation of the sample with defined stoichiometry easier, especially when the elements have different sputtering rates.
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Affiliation(s)
- Sergey V. Ketov
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
| | - Xuetao Shi
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
| | - Guoqiang Xie
- Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
| | - Ryotaro Kumashiro
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
| | | | - Andrey I. Bazlov
- National University of Science and Technology ″MISiS″, Moscow, Russia
| | - Na Chen
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Yoshifumi Ishikawa
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Naoki Asao
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
| | - Hongkai Wu
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba-Ku, Sendai 980-8577, Japan
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Gleiter H. Nanoglasses: a new kind of noncrystalline materials. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2013; 4:517-533. [PMID: 24062978 PMCID: PMC3778333 DOI: 10.3762/bjnano.4.61] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 08/29/2013] [Indexed: 05/31/2023]
Abstract
Nanoglasses are a new class of noncrystalline solids. They differ from today's glasses due to their microstructure that resembles the microstructure of polycrystals. They consist of regions with a melt-quenched glassy structure connected by interfacial regions, the structure of which is characterized (in comparison to the corresponding melt-quenched glass) by (1) a reduced (up to about 10%) density, (2) a reduced (up to about 20%) number of nearest-neighbor atoms and (3) a different electronic structure. Due to their new kind of atomic and electronic structure, the properties of nanoglasses may be modified by (1) controlling the size of the glassy regions (i.e., the volume fraction of the interfacial regions) and/or (2) by varying their chemical composition. Nanoglasses exhibit new properties, e.g., a Fe90Sc10 nanoglass is (at 300 K) a strong ferromagnet whereas the corresponding melt-quenched glass is paramagnetic. Moreover, nanoglasses were noted to be more ductile, more biocompatible, and catalytically more active than the corresponding melt-quenched glasses. Hence, this new class of noncrystalline materials may open the way to technologies utilizing the new properties.
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Affiliation(s)
- Herbert Gleiter
- Institute of Nanotechnology, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe, Germany and Nanjing University of Science and Technology, Herbert Gleiter Institute of Nanoscience, Building 340, Nanjing, Jiangsu 2 10094, P. R. China
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8
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Baumer RE, Demkowicz MJ. Glass transition by gelation in a phase separating binary alloy. PHYSICAL REVIEW LETTERS 2013; 110:145502. [PMID: 25167007 DOI: 10.1103/physrevlett.110.145502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Indexed: 06/03/2023]
Abstract
We use molecular dynamics simulations to show that glass transition in a model phase separating amorphous alloy, Cu(50)Nb(50), occurs by gelation. At the glass transition, a mechanically stiff, percolating network of atoms with icosahedral local packing forms at the interfaces between compositionally enriched regions. This low-energy network halts coarsening of the phase-separated structure and imparts shear resistance. These features of glass transition are remarkably similar to gelation processes in polymeric and colloidal gels.
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Affiliation(s)
- R E Baumer
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - M J Demkowicz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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10
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ZHANG ZHENGJUN, ZHOU YA, YUE YANG. GROWTH CARBON NANOTUBES DIRECTLY ON PRISTINE SILICON SUBSTRATES. INTERNATIONAL JOURNAL OF NANOSCIENCE 2011. [DOI: 10.1142/s0219581x06004590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
It is believed that carbon nanotubes were not able to grow on silicon substrates by chemical vapor deposition from a mixture of ferrocene and xylene. This is because iron particles (formed by the decomposition of ferrocene) reacted quickly with silicon to form a discontinuous layer (> 100 nm ) of FeSi 2 and Fe 2 SiO 4 particles. We report, in this letter, that by controlling the growth kinetics, aligned carbon nanotubes could be grown on pristine silicon substrates. The reason is that appropriate growth conditions could slow down and suppress the reaction within the very surface region to form an almost continuous thin layer (< 10 nm ) of Fe 2 SiO 4 particles; thus preventing further reaction and leaving a number of iron particles still active to catalyze the growth of carbon nanotubes. The structure and field emission properties of the nanotubes were also investigated.
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Affiliation(s)
- ZHENGJUN ZHANG
- Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - YA ZHOU
- Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - YANG YUE
- Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
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11
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Srivastava C, Sinha SK. Ultra fine scale phase separated microstructure for Ag–Fe nanoparticle. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.08.052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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12
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Bose S, Puthucode A, Banerjee R, Ayyub P. The influence of nanoscale phase separation and devitrification on the electrical transport properties of amorphous Cu-Nb alloy thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:285305. [PMID: 21828518 DOI: 10.1088/0953-8984/21/28/285305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The formation of amorphous phases in immiscible alloys with a large positive enthalpy of mixing is thermodynamically unfavorable. Co-sputter deposited Cu-Nb films exhibit a nanoscale phase separation into Cu-rich and Nb-rich amorphous regions. They show relatively high room temperature resistivity, a negative temperature coefficient of resistance (TCR), and an incomplete superconducting transition with onset at 3.7 K. Annealing the nanophase-separated amorphous films at 200 °C results in the nucleation of fcc Cu-rich nanocrystals within an Nb-rich amorphous matrix. This film exhibits multiple resistance steps, eventually showing a sharp drop with (T(C))(onset) = 3.7 K. Annealing at 350 °C leads to complete devitrification via the formation of large bcc Nb-rich grains encapsulating the existing fcc Cu nanocrystals. These films show low room temperature resistivity, positive TCR, and a sharp superconducting transition with onset at 5.2 K. The electrical transport and superconducting behavior appear to be consistent with a two-stage crystallization process.
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Affiliation(s)
- Sangita Bose
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005, India
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13
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Kong Y, Kong LT, Liu BX. First-principles calculations of the structural stability and magnetic property of the metastable phases in the equilibrium immiscible Co-Au system. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:4345-4353. [PMID: 21690786 DOI: 10.1088/0953-8984/18/17/020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
To reveal the energetic sequence of the alloy phases in the Co-Au system, the lattice constants, cohesive energies, and bulk modulus of the fcc Au, hcp Co, the B1, B2, and L1(0) structured CoAu phases, and the D0(3), L1(2), and D0(19) structured Co(3)Au and CoAu(3) phases, respectively, are acquired by first-principles calculations within the generalized-gradient approximation (GGA) as well as within the local density approximation (LDA). In addition, the magnetic moment of the Co atom in the studied phases are also calculated. To further examine the structural stability, the elastic constants of the studied phases are calculated and the results suggest that the fcc-type structures could be elastically stable at Co/Au = 1:3, 1:1, and 3:1, whereas the hcp-type structures could be stable at Co/Au = 1:3 and 3:1. Moreover, the spatial valence charge density (SVCD) and spin density of the studied phases are also calculated to clarify the physical origin of the structural stability. It turns out that, in the relatively stable phases, the high SVCDs mostly distribute between the similar atoms, thus forming the attractive covalent bonding to stabilize the respective structures, and that the spin density may also play an important role in influencing the stability of the ferromagnetic metastable phases.
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Affiliation(s)
- Y Kong
- Advanced Materials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China. State Key Laboratory of Solid-State Microstructure, Nanjing University, Nanjing 200039, People's Republic of China
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He JH, Carosella CA, Hubler GK, Qadri SB, Sprague JA. Bombardment-induced tunable superlattices in the growth of Au-Ni films. PHYSICAL REVIEW LETTERS 2006; 96:056105. [PMID: 16486960 DOI: 10.1103/physrevlett.96.056105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Indexed: 05/06/2023]
Abstract
Highly ordered superlattices are typically created through the sequential deposition of two different materials. Here, we report our experimental observation of spontaneous formation of superlattices in coevaporation of Au and Ni under energetic ion bombardment. The superlattice periodicities are on the order of a few nanometers and can be adjusted through the energy and flux of ion beams. Such a self-organization process is a consequence of the bombardment-induced segregation and uphill diffusion within the advancing nanoscale subsurface zone in the film growth. Our observations suggest that ion beams can be employed to make tunable natural superlattices in the deposition of phase-separated systems with strong bombardment-induced segregation.
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Affiliation(s)
- J H He
- Naval Research Laboratory, Washington, DC 20375, USA.
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15
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Li JH, Kong LT, Liu BX. Proposed Definition of Microchemical Inhomogeneity and Application To Characterize Some Selected Miscible/Immiscible Binary Metal Systems. J Phys Chem B 2004. [DOI: 10.1021/jp047897x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. H. Li
- Advanced Materials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - L. T. Kong
- Advanced Materials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - B. X. Liu
- Advanced Materials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
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Sheng HW, Ma E. Atomic packing of the inherent structure of simple liquids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:062202. [PMID: 15244642 DOI: 10.1103/physreve.69.062202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2003] [Indexed: 05/24/2023]
Abstract
We report a universal inherent packing structure underlying the simple liquids, the normalized distribution functions of which are independent of temperature and density. The inherent packing state, carrying the maximized configurational entropy, has intrinsic connections with the maximally random jammed state of hard spheres.
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Affiliation(s)
- H W Sheng
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.
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17
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Luo WK, Sheng HW, Alamgir FM, Bai JM, He JH, Ma E. Icosahedral short-range order in amorphous alloys. PHYSICAL REVIEW LETTERS 2004; 92:145502. [PMID: 15089549 DOI: 10.1103/physrevlett.92.145502] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2002] [Indexed: 05/24/2023]
Abstract
We have characterized the icosahedral short-range order in amorphous solids using local environment probes. Such topological local order is pronounced even in an amorphous alloy that does not form quasicrystalline phases upon crystallization, as demonstrated by the extended x-ray absorption fine structure and x-ray absorption near-edge structure of a Ni-Ag amorphous alloy analyzed through reverse Monte Carlo simulations.
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Affiliation(s)
- W K Luo
- Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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18
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He JH, Sheng HW, Lin JS, Schilling PJ, Tittsworth RC, Ma E. Homogeneity of a supersaturated solid solution. PHYSICAL REVIEW LETTERS 2002; 89:125507. [PMID: 12225100 DOI: 10.1103/physrevlett.89.125507] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2002] [Indexed: 05/23/2023]
Abstract
Extended x-ray absorption fine structures, small-angle x-ray scattering, and atomistic model calculations have been employed to probe the homogeneity of the fcc solution created in Ag-Cu, a classical system demonstrating the extension of solubility across the entire miscibility gap through rapid quenching. Our results reveal that in many cases the supersaturated solutions formed have decomposition features on the scale of 1 nm. Conventional diffraction methods are inadequate in determining the level of supersaturation or the uniformity of such solid solution alloys.
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Affiliation(s)
- J H He
- Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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