INTEGRAL-EQUATION APPROACH TO MEDIUM-RANGE ORDER IN MOLTEN AND GLASSY CHALCOGENIDES

被引:50
作者
IYETOMI, H
VASHISHTA, P
KALIA, RK
机构
[1] Materials Science Division, Argonne National Laboratory, Argonne
来源
PHYSICAL REVIEW B | 1991年 / 43卷 / 02期
关键词
D O I
10.1103/PhysRevB.43.1726
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The first sharp diffraction peak (FSDP), a signature of medium-range order in molten and vitreous chalcogenides, is investigated using the integral-equation method. A variety of interatomic potentials, including uncharged and charged hard spheres, and realistic two-body interactions, are used in this study. The two-body potential consists of steric repulsions, Coulomb interactions due to charge-transfer effects, and the effects of electronic polarizability of ions. GeSe2 is treated as a specific example. The FSDP is observed in both the charged-hard-sphere and the realistic two-body interaction models. In both models steric and charge-transfer effects are found to give rise to Ge(Se1/2)4 tetrahedra whose packing determines the medium-range order and the attendant FSDP. From the charge-charge structure factor it is found that the FSDP arises from spatial correlations where charge neutrality prevails. The nature of the medium-range correlation is elucidated through the temperature and density dependence of the FSDP and the thermal expansion determined from the shifts of the peaks in the static structure factor. We have also studied the effects of the potential parameters on the position of the FSDP. The results of the hypernetted-chain theory are compared with the molecular-dynamics results.
引用
收藏
页码:1726 / 1734
页数:9
相关论文
共 49 条
[1]   NEW METHOD OF SOLVING THE HNC EQUATION FOR IONIC LIQUIDS [J].
ABERNETHY, GM ;
GILLAN, MJ .
MOLECULAR PHYSICS, 1980, 39 (04) :839-847
[2]   STRUCTURE OF BINARY LIQUID MIXTURES .I. [J].
ASHCROFT, NW ;
LANGRETH, DC .
PHYSICAL REVIEW, 1967, 156 (03) :685-&
[3]  
ASHCROFT NW, 1968, PHYS REV, V166, pE934
[4]   WHAT IS LIQUID - UNDERSTANDING STATES OF MATTER [J].
BARKER, JA ;
HENDERSON, D .
REVIEWS OF MODERN PHYSICS, 1976, 48 (04) :587-671
[5]   STATISTICAL-MECHANICS OF SIMPLE COULOMB-SYSTEMS [J].
BAUS, M ;
HANSEN, JP .
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 1980, 59 (01) :1-94
[6]   INTERATOMIC POTENTIALS FOR SILICON STRUCTURAL ENERGIES [J].
BISWAS, R ;
HAMANN, DR .
PHYSICAL REVIEW LETTERS, 1985, 55 (19) :2001-2004
[7]   NEW CLASSICAL-MODELS FOR SILICON STRUCTURAL ENERGIES [J].
BISWAS, R ;
HAMANN, DR .
PHYSICAL REVIEW B, 1987, 36 (12) :6434-6445
[8]   TEMPERATURE-DEPENDENCE OF THE STRUCTURE FACTOR OF AS2SE3 GLASS UP TO THE GLASS-TRANSITION [J].
BUSSE, LE ;
NAGEL, SR .
PHYSICAL REVIEW LETTERS, 1981, 47 (25) :1848-1851
[9]  
Dixon M., 1977, Physics and Chemistry of Liquids, V6, P189, DOI 10.1080/00319107708084139
[10]   EXTENSION OF THE OPTIMIZED RHNC EQUATION TO MULTICOMPONENT LIQUIDS [J].
ENCISO, E ;
LADO, F ;
LOMBARDERO, M ;
ABASCAL, JLF ;
LAGO, S .
JOURNAL OF CHEMICAL PHYSICS, 1987, 87 (04) :2249-2256