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Du Y, Li W, Zurek E, Gao L, Cui X, Zhang M, Liu H, Tian Y, Zhang S, Zhang D. Predicted CsSi compound: a promising material for photovoltaic applications. Phys Chem Chem Phys 2020; 22:11578-11582. [PMID: 32400781 DOI: 10.1039/d0cp01440k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Exploration of photovoltaic materials has received enormous interest for a wide range of both fundamental and applied research. Therefore, in this work, we identify a CsSi compound with a Zintl phase as a promising candidate for photovoltaic material by using a global structure prediction method. Electronic structure calculations indicate that this phase possesses a quasi-direct band gap of 1.45 eV, suggesting that its optical properties could be superior to those of diamond-Si for capturing sunlight from the visible to the ultraviolet range. In addition, a novel silicon allotrope is obtained by removing Cs atoms from this CsSi compound. The superconducting critical temperature (Tc) of this phase was estimated to be of 9 K in terms of a substantial density of states at the Fermi level. Our findings represent a new promising CsSi material for photovoltaic applications, as well as a potential precursor of a superconducting silicon allotrope.
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Affiliation(s)
- Yonghui Du
- School of Materials Science and Engineering, Beihua University, Jilin 132013, China
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2
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Bhattacharya A. Deviation from guest dominated glass like lattice dynamics in prototypical ternary Ba 8Ni x Ge[Formula: see text] clathrates. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:175502. [PMID: 31935696 DOI: 10.1088/1361-648x/ab6b89] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Intermetallic guest filled clathrate cages have been identified as promising materials for thermoelectric applications. The structure, electronic structure, and phonon dynamics of type-I Ba filled Ni substituted Ge clathrates have been explored using density-functional theory. The formation energy of type-I Ba8Ni x Ge[Formula: see text] clathrates with y vacancies [Formula: see text] in their framework is calculated as a function of concentration of Ni substitution x. Metal substitution i.e. with Ni destabilized the framework vacancies resulting in a framework devoid of vacancies beyond a particular concentration of Ni substituition (for [Formula: see text]). By tuning the concentration of Ni in the framework, n-type to p -type doping can be achieved while retaining the compositional homogeinity. Furthermore, Ni substitution in the framework lowered the thermal conductivity of these compounds. Results of molecular dynamics simulations showed that with the increase in temperature the guest, the substitutional host as well as the host atoms rattled to collectively lower the lattice thermal conductivity of these clathrates. This is found to be contradictory to the concept of guest dominated glass like phonon dynamics in these compounds.
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Affiliation(s)
- Amrita Bhattacharya
- Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay, Powai-400076, Mumbai, Maharashtra, India
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First-Principles Analysis of Vibrational Properties of Type II SiGe Alloy Clathrates. NANOMATERIALS 2019; 9:nano9050723. [PMID: 31083355 PMCID: PMC6566651 DOI: 10.3390/nano9050723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/04/2019] [Accepted: 05/07/2019] [Indexed: 11/23/2022]
Abstract
We have mostly performed vibrational studies of Type-II silicon-germanium clathrate alloys, namely, Si136-xGex (0 < x ≤ 128), using periodic density functional theory (DFT). Our computed lattice constant for various stoichiometric amount, namely, x, of Ge agrees to some extent with the observed X-ray diffraction (XRD) data, along with monotonically increasing dependence on x. According to our bandgap energy calculation via Vienna ab initio simulation package (VASP), Si128Ge8 has a “nearly-direct” bandgap of approximately 1.27 eV, which agrees well with the previously calculated result (~1.23 eV), which was obtained using the Cambridge sequential simulation total energy package (CASTEP). Most of our first-principles calculations focus on exploring the low-energy transverse acoustic (TA) phonons that contribute dominantly to the induction of negative thermal expansion (NTE) behavior. Moreover, our work has predicted that the Si104Ge32 framework exhibits NTE in the temperature range of 3–80 K, compared to the temperature regime (10–140 K) of NTE observed in such pure Si136. It is posited that the increased number of Ge–Ge bonds may weaken the NTE effect substantially, as the composition, which is denoted as x, in Si136-xGex is elevated from 32 (or 40) to 96 (or 104).
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He M, Zhao Y, Wang B, Xi Q, Zhou J, Liang Z. 3D Printing Fabrication of Amorphous Thermoelectric Materials with Ultralow Thermal Conductivity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:5889-94. [PMID: 26448629 DOI: 10.1002/smll.201502153] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/25/2015] [Indexed: 05/20/2023]
Abstract
Thermoelectric materials are prepared by developing 3D printing technology. The 3D fabricated Bi0.5 Sb1.5 Te3 samples exhibit amorphous characteristics and thus show an ultralow thermal conductivity of 0.2 W m(-1) K(-1) . 3D printing fabrication readily generates bulk thermoelectric samples of any shape, which is not the case with traditional hot-pressing and spark plasma sintering methods.
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Affiliation(s)
- Minhong He
- Department of Materials Science, Fudan University, Shanghai, 200433, China
| | - Yan Zhao
- Department of Materials Science, Fudan University, Shanghai, 200433, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Biao Wang
- Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Qing Xi
- Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Jun Zhou
- Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Ziqi Liang
- Department of Materials Science, Fudan University, Shanghai, 200433, China
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Stefanoski S, Martin J, Nolas GS. Low temperature transport properties and heat capacity of single-crystal Na8Si46. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:485404. [PMID: 21406746 DOI: 10.1088/0953-8984/22/48/485404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The low temperature thermal conductivity, resistivity, and Seebeck coefficient of single-crystal Na(8)Si(46) are investigated revealing the intrinsic low temperature transport properties of this material. Metallic conduction is observed, with a higher residual resistance ratio than any other known type I clathrate. Heat capacity together with thermal conductivity provide insight into the Na disorder inside the polyhedra formed by the Si framework. Single-crystal structural refinement and thermal property analyses reveal anisotropic disorder for Na inside the tetrakaidecahedra due to a reduction in the symmetry inside these polyhedra, unlike that for Na inside the dodecahedra.
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Affiliation(s)
- S Stefanoski
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
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Cros C, Pouchard M. Sur les phases de type clathrate du silicium et des éléments apparentés (C, Ge, Sn) : Une approche historique. CR CHIM 2009. [DOI: 10.1016/j.crci.2009.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Takasu Y, Hasegawa T, Ogita N, Udagawa M, Avila MA, Suekuni K, Takabatake T. Off-center rattling and anisotropic expansion of type-I clathrates studied by Raman scattering. PHYSICAL REVIEW LETTERS 2008; 100:165503. [PMID: 18518215 DOI: 10.1103/physrevlett.100.165503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Indexed: 05/26/2023]
Abstract
Dynamical motions of the guest ions in type-I clathrates Sr8Ga16Si(30-x)Gex and Ba8Ga16Si(30-x)Gex have been studied by Raman scattering spectroscopy, to clarify the role of guest vibration modes in these systems with unusual thermal transport behaviors. An anomalous decrease of the guest energies with decreasing temperature is observed for both systems. The Ge-doping expands the cage surrounding the 6d site anisotropically for Sr8Ga16Si(30-x)Gex, but isotropically for Ba8Ga16Si(30-x)Gex. Especially for Sr8Ga16Si(30-x)Gex, off-center rattling arises simultaneously with the anisotropic expansion, and it is confirmed that these anomalies play a crucial role to suppress lattice thermal conductivity in these systems.
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Affiliation(s)
- Y Takasu
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8521, Japan
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9
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Beekman M, Nolas GS. Inorganic clathrate-II materials of group 14: synthetic routes and physical properties. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b706808e] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Tse JS, Klug DD, Zhao JY, Sturhahn W, Alp EE, Baumert J, Gutt C, Johnson MR, Press W. Anharmonic motions of Kr in the clathrate hydrate. NATURE MATERIALS 2005; 4:917-21. [PMID: 16267573 DOI: 10.1038/nmat1525] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2005] [Accepted: 09/30/2005] [Indexed: 05/05/2023]
Abstract
The anomalous glass-like thermal conductivity of crystalline clathrates has been suggested to be the result of the scattering of thermal phonons of the framework by 'rattling' motions of the guests in the clathrate cages. Using the site-specific (83)Kr nuclear resonant inelastic scattering spectroscopy in combination with conventional incoherent inelastic neutron scattering and molecular-dynamics simulations, we provide unambiguous evidence and characterization of the effects on these guest-host interactions in a structure-II Kr clathrate hydrate. The resonant scattering of phonons led to unprecedented large anharmonic motions of the guest atoms. The anharmonic interaction underlies the anomalous thermal transport in this system. Clathrates are prototypical models for a class of crystalline framework materials with glass-like thermal conductivity. The explanation of the unusual molecular dynamics has a wide implication for the understanding of the thermal properties of disordered solids and structural glasses.
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Affiliation(s)
- J S Tse
- Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, K1A 0R6, Canada.
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Yang L, Wang Y, Liu T, Hu T, Li B, Ståhl K, Chen S, Li M, Shen P, Lu G, Wang Y, Jiang J. Copper position in type-I Ba8Cu4Si42 clathrate. J SOLID STATE CHEM 2005. [DOI: 10.1016/j.jssc.2005.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Krivchikov AI, Manzhelii VG, Korolyuk OA, Gorodilov BY, Romantsova OO. Thermal conductivity of tetrahydrofuran hydrate. Phys Chem Chem Phys 2005; 7:728-30. [DOI: 10.1039/b418602h] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Blase X, Gillet P, San Miguel A, Mélinon P. Exceptional ideal strength of carbon clathrates. PHYSICAL REVIEW LETTERS 2004; 92:215505. [PMID: 15245291 DOI: 10.1103/physrevlett.92.215505] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2003] [Indexed: 05/24/2023]
Abstract
We study by means of ab initio calculations the ideal tensile and shear strengths of the C-46 clathrate phase. While its bulk modulus and elastic constants are smaller than in diamond, its strength is found to be in all directions larger than the critical stresses associated with the diamond [111] planes of easy slip. This can be related to the frustration by the clathrate cage structure of the diamond to graphite instability under nonhydrostatic stress conditions [corrected] The criteria for designing strong materials are discussed.
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Affiliation(s)
- X Blase
- Laboratoire de Physique de la Matière Condensée et des Nanostructures, Université Claude Bernard Lyon I and CNRS, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
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Conesa JC, Tablero C, Wahnon P. First principles calculations of electronic structures and metal mobility of NaxSi46 and NaxSi34 clathrates. J Chem Phys 2004; 120:6142-51. [PMID: 15267500 DOI: 10.1063/1.1650303] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Energetics, geometry, electronic band structures, and charge transfer for Na(x)Si(46) and Na(x)Si(34) clathrates with different degrees of cavity filling by sodium, and the mobility of the Na atom inside the different cavities are studied using first principles density functional calculations within the generalized gradient approximation. The stabilization of the clathrate lattice and the cell volume variation upon the inclusion of Na (which appears to move easily in the larger cavities of Na(x)Si(34), thus justifying the experimental observations) are discussed in connection with the onset of the repulsion between Na and Si for distances shorter than approximately 3.4 A. For all degrees of filling of the different cavities examined we find that the electron population of the s orbitals in the partially ionized Na atoms increases with a decrease in the size of the cavity, and that the Na states contribute significantly to the density of states at the Fermi level and thus influence the properties of these compounds.
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Affiliation(s)
- J C Conesa
- Instituto de Catalisis y Petroleoquimica, C.S.I.C., Campus de Cantoblanco, 28049 Madrid, Spain
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15
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Connétable D, Timoshevskii V, Masenelli B, Beille J, Marcus J, Barbara B, Saitta AM, Rignanese GM, Mélinon P, Yamanaka S, Blase X. Superconductivity in doped sp3 semiconductors: the case of the clathrates. PHYSICAL REVIEW LETTERS 2003; 91:247001. [PMID: 14683147 DOI: 10.1103/physrevlett.91.247001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Indexed: 05/24/2023]
Abstract
We present a joint experimental and theoretical study of the superconductivity in doped silicon clathrates. The critical temperature in Ba(8)@Si-46 is shown to strongly decrease with applied pressure. These results are corroborated by ab initio calculations using MacMillan's formulation of the BCS theory with the electron-phonon coupling constant lambda calculated from perturbative density functional theory. Further, the study of I(8)@Si-46 and of gedanken pure silicon diamond and clathrate phases doped within a rigid-band approach show that the superconductivity is an intrinsic property of the sp(3) silicon network. As a consequence, carbon clathrates are predicted to yield large critical temperatures with an effective electron-phonon interaction much larger than in C60.
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Affiliation(s)
- D Connétable
- LPMCN, Université Claude Bernard Lyon I and CNRS, UMR 5586, Bâtiment Brillouin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
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Kume T, Fukuoka H, Koda T, Sasaki S, Shimizu H, Yamanaka S. High-pressure Raman study of Ba doped silicon clathrate. PHYSICAL REVIEW LETTERS 2003; 90:155503. [PMID: 12732046 DOI: 10.1103/physrevlett.90.155503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2002] [Indexed: 05/24/2023]
Abstract
Vibrational properties of Ba doped Si clathrate are investigated at high pressures up to 20 GPa by Raman spectroscopy. Vibrations related with Ba encaged in the Si cages are observed below 100 cm(-1) by low-frequency Raman measurements of Ba8Si46 and Ba6.6Si46 clathrates. The high-pressure Raman spectra obtained for both compression and decompression processes reveal a new phase transition at 7 GPa, and the reversibility of the phase transition at 15 GPa. We investigate the mechanisms of these phase transitions, the interaction between the guest and host frame, and the volume dependence of the vibrational modes.
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Affiliation(s)
- Tetsuji Kume
- Department of Materials Science and Technology, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
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Tse JS, Desgreniers S, Li ZQ, Ferguson MR, Kawazoe Y. Structural stability and phase transitions in K8Si46 clathrate under high pressure. PHYSICAL REVIEW LETTERS 2002; 89:195507. [PMID: 12443127 DOI: 10.1103/physrevlett.89.195507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2002] [Indexed: 05/24/2023]
Abstract
The structural stability of type-I K8Si46 clathrate has been investigated at high pressure by synchrotron x-ray diffraction. In contrast to that observed in the Na-doped structure-II analogue [A. San-Miguel, Phys. Rev. Lett. 83, 5290 (1999)]], no phase separation into the beta-Sn Si structure was identified at 11 GPa. Instead, K8Si46 is found to undergo a transition to an isostructural positional disordered phase at around 15 GPa. Ab initio phonon band structure calculations reveal a novel phenomenon of phonon instabilities of K atoms in the large cavities is responsible for this transition. Above 32 GPa, the new structure transforms into an amorphous phase.
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Affiliation(s)
- John S Tse
- Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6.
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Lee S, Hoffmann R. Bcc and Fcc transition metals and alloys: a central role for the Jahn-Teller effect in explaining their ideal and distorted structures. J Am Chem Soc 2002; 124:4811-23. [PMID: 11971731 DOI: 10.1021/ja0114557] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transition metal elements, alloys, and intermetallic compounds often adopt the body centered cubic (bcc) and face centered cubic (fcc) structures. By comparing quantitative density functional with qualitative tight-binding calculations, we analyze the electronic factors which make the bcc and fcc structures energetically favorable. To do so, we develop a tight-binding function, DeltaE(star), a function that measures the energetic effects of transferring electrons within wave vector stars. This function allows one to connect distortions in solids to the Jahn-Teller effect in molecules and to provide an orbital perspective on structure determining deformations in alloys. We illustrate its use by considering first a two-dimensional square net. We then turn to three-dimensional fcc and bcc structures, and distortions of these. Using DeltaE(star), we rationalize the differences in energy of these structures. We are able to deduce which orbitals are responsible for instabilities in seven to nine valence electron per atom (e(-)/a) bcc systems and five and six e(-)/a fcc structures. Finally we demonstrate that these results account for the bcc and fcc type structures found in both the elements and binary intermetallic compounds of group 4 through 9 transition metal atoms. The outline of a theory of metal structure deformations based on loss of point group operation rather than translational symmetry is presented.
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Affiliation(s)
- Stephen Lee
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA
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20
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Gutt C, Baumert J, Press W, Tse JS, Janssen S. The vibrational properties of xenon hydrate: An inelastic incoherent neutron scattering study. J Chem Phys 2002. [DOI: 10.1063/1.1446426] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Connétable D, Timoshevskii V, Artacho E, Blase X. Tailoring band gap and hardness by intercalation: an ab initio Study of I(8)@Si-46 and related doped clathrates. PHYSICAL REVIEW LETTERS 2001; 87:206405. [PMID: 11690498 DOI: 10.1103/physrevlett.87.206405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2001] [Indexed: 05/23/2023]
Abstract
We present an ab initio study of the structural and electronic properties of the recently synthesized I(8)@Si-46 clathrate which is shown to be a degenerate p-type doped system. The intercalation significantly opens the band gap to a 1.75 eV value within the density functional theory. We study further the intercalation by other neighboring elements. A quasiparticle study reveals that such systems can display a band gap in the "green-light" energy range. Finally, we show that the bulk modulus can be increased to values equivalent to the one of the diamond phase.
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Affiliation(s)
- D Connétable
- Département de Physique des Matériaux and CNRS, Université Claude Bernard-Lyon 1, Bâtiment 203, 43 Bd du 11, Novembre 1918, 69622 Villeurbanne Cédex, France
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Dong J, Sankey OF, Myles CW. Theoretical study of the lattice thermal conductivity in Ge framework semiconductors. PHYSICAL REVIEW LETTERS 2001; 86:2361-2364. [PMID: 11289929 DOI: 10.1103/physrevlett.86.2361] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2000] [Indexed: 05/23/2023]
Abstract
The lattice thermal conductivity of Ge clathrates is investigated by evaluating the linear response theory heat current correlation functions using molecular dynamics. Clathrate crystals with and without guest atoms in their fullerane cages are studied. In comparison with that of diamond-phase Ge, the clathrate conductivity is reduced by approximately 1 order of magnitude due to the open framework itself. The addition of an encapsulated (rattling) Sr guest atom produces a further order of magnitude reduction in the conductivity, making it comparable to that of amorphous Ge. Our results are consistent with experiments, and have impact on the search for improved thermoelectric materials.
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Affiliation(s)
- J Dong
- Department of Physics and Astronomy, Arizona State University, Tempe 85285-1504, USA
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