Long-period structures in noble-metal alloys: New aspects

被引：1
作者：
Velikokhatnii O.I. [1 ,2 ]
Eremeev S.V. [1 ,2 ]
Naumov I.I. [1 ,2 ]
Potekaev A.I. [1 ,2 ]
机构：
[1] V. D. Kuznetsov Siberian Physico-Technical Institute, Tomsk State University
[2] Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences
来源：
Russian Physics Journal | 2001年 / 44卷 / 2期
关键词：
Fermi Surface; Perpendicular Direction; Intermediate Position; Precise Calculation; Antiphase Boundary;
D O I：
10.1023/A:1011313701802
中图分类号：
学科分类号：
摘要：
Proceeding from precise calculation of the electronic structure and the generalized electronic susceptibility, a systematic study of the relationship between the nesting properties of the Fermi surface (FS) and the character of long-period ordered superstructures (LPSs) in noble-metal alloys, Cu-Au, Cu-Pd, and Ag-Mg, is performed. An answer is provided as to why in Cu-Au, Cu-Pd, and Cu-Pt alloys so-called incommensurate LPSs, characterized by an irrational period and smeared antiphase boundaries, are formed. The reasons for occurrence of such LPSs within a short temperature range only are clarified. The dependence of the long period M on the long-range order parameter η in Cu-Au alloys is accounted for. The causes for formation of two-dimensional LPSs in Au3Cu and Cu3Pd alloys are found. It is shown that their stability may be explained for by energy gaps opening on coinciding patches of FS in two mutually perpendicular directions. Arguments are drawn in favor of the fact that among quasicrystalline substances, phases with incommensurate LPSs occupy an intermediate position between incommensurate systems and quasicrystals. An attempt is made to identify the reasons for qualitatively different behavior of LPSs with large and small superperiods. It is shown that the dependence of LPS's behavior on the value of 2M is controlled by the quality of nesting on FS and the nesting vector sensitivity (2kF) to variations in the long-range order parameter η. ©2001 Plenum Publishing Corporation.
引用
收藏
页码：131 / 144
页数：13
相关论文
共 41 条
[11]  
Sato H., Toth R.S., Phys. Rev., 124, (1961)
[12]  
Sato H., Toth R.S., Phys. Rev., 127, (1962)
[13]  
Toth R.S., Sato H., J. Appl. Phys., 33, (1962)
[14]  
Tachiki M., Teramoto K., J. Phys. Chem. Solids, 28, (1966)
[15]  
Dement'ev V.M., Kozlov E.V., Izv. Vyssh. Uvhebn. Zaved. Fiz., 6, pp. 21-33, (1973)
[16]  
Dement'ev V.M., Kozlov E.V., Izv. Vyssh. Uvhebn. Zaved. Fiz., 6, pp. 30-42, (1974)
[17]  
Vul D.A., Krivoglaz M.A., Fiz. Met. Metalloved., 51, (1981)
[18]  
Vul D.A., Krivoglaz M.A., Fiz. Met. Metalloved., 55, (1983)
[19]  
Krivoglaz M.A., Sov. Phys. JETP, 57, (1983)
[20]  
Krivoglaz M.A., Diffuse Scattering of X-rays and Neutrons by Fluctuation Nanuniformities in Nonperfect Crystals [in Russian], (1984)
12345