EFFECTS OF DISORDER ON THE VIBRATIONAL PROPERTIES OF SIGE ALLOYS - FAILURE OF MEAN-FIELD APPROXIMATIONS

被引：46

作者：

DEGIRONCOLI, S ^{[1
]}

BARONI, S ^{[1
]}

机构：

[1] SISSA,I-34014 TRIESTE,ITALY

来源：

PHYSICAL REVIEW LETTERS | 1992年 / 69卷 / 13期

关键词：

D O I：

10.1103/PhysRevLett.69.1959

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The vibrational properties of Si1/2Ge1/2 alloys are studied using first principles interatomic force constants. The effects of disorder are either simulated using large supercells or treated at the mean-field level by the coherent-potential approximation. The latter approach fails not only to reproduce the details of the Raman spectra due to the local atomic environment, but even to predict the three-mode behavior of this alloy. Supercell calculations, on the contrary, are in good agreement with observed Raman spectra and shed light on the microscopic mechanisms responsible for their detailed features.

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页码：1959 / 1962

页数：4

相关论文

共 16 条

[1] RAMAN-SPECTRA OF C-SI1-XGEX ALLOYS [J].

ALONSO, MI ;

WINER, K .

PHYSICAL REVIEW B, 1989, 39 (14) :10056-10062

[2] PHONON DISPERSIONS IN GAXAL1-XAS ALLOYS [J].

BARONI, S ;

DEGIRONCOLI, S ;

GIANNOZZI, P .

PHYSICAL REVIEW LETTERS, 1990, 65 (01) :84-87

[3] GREEN-FUNCTION APPROACH TO LINEAR RESPONSE IN SOLIDS [J].

BARONI, S ;

GIANNOZZI, P ;

TESTA, A .

PHYSICAL REVIEW LETTERS, 1987, 58 (18) :1861-1864

[4] ELECTRONIC STRUCTURE OF LIQUID INSULATORS [J].

BEEBY, JL ;

EDWARDS, SF .

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1963, 274 (1356) :395-+

[5] VIBRATIONAL PROPERTIES AND INFRARED-SPECTRA OF ALXGA1-XAS SYSTEMS .1. AVERAGE-T-MATRIX APPROXIMATION VERSUS SUPERCELL CALCULATION FOR HOMOGENEOUS ALLOYS [J].

BERNASCONI, M ;

COLOMBO, L ;

MIGLIO, L ;

BENEDEK, G .

PHYSICAL REVIEW B, 1991, 43 (18) :14447-14456

[6] VIBRATIONAL PROPERTIES AND INFRARED-SPECTRA OF ALXGA1-XAS SYSTEMS .2. ORDER AND DISORDER FEATURES IN SUPERLATTICE CONFIGURATION [J].

BERNASCONI, M ;

COLOMBO, L ;

MIGLIO, L .

PHYSICAL REVIEW B, 1991, 43 (18) :14457-14464

[7] PHONONS IN SI-GE SYSTEMS - AN ABINITIO INTERATOMIC-FORCE-CONSTANT APPROACH [J].

DEGIRONCOLI, S .

PHYSICAL REVIEW B, 1992, 46 (04) :2412-2419

[8]

DEGIRONCOLI S, 1992, 21ST P INT C PHYS SE

[9] ABINITIO CALCULATION OF PHONON DISPERSIONS IN SEMICONDUCTORS [J].

GIANNOZZI, P ;

DE GIRONCOLI, S ;

PAVONE, P ;

BARONI, S .

PHYSICAL REVIEW B, 1991, 43 (09) :7231-7242

[10] DISPERSIVE CHARACTER OF OPTICAL PHONONS IN GAALAS ALLOYS FROM RAMAN-SCATTERING IN SUPERLATTICES [J].

JUSSERAND, B ;

PAQUET, D ;

MOLLOT, F .

PHYSICAL REVIEW LETTERS, 1989, 63 (21) :2397-2400