SURFACE SEGREGATION ON FE3AL(110) NEAR THE ORDER-DISORDER TRANSITION-TEMPERATURE

被引：21

作者：

VOGES, D ^{[1
]}

TAGLAUER, E ^{[1
]}

DOSCH, H ^{[1
]}

PEISL, J ^{[1
]}

机构：

[1] UNIV MUNICH, SEKT PHYS, W-8000 MUNICH 2, GERMANY

来源：

SURFACE SCIENCE | 1992年 / 269卷

关键词：

D O I：

10.1016/0039-6028(92)91406-2

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The Fe3Al alloy undergoes a bulk order-disorder transition at a critical temperature of 780 K. The question of possible surface segregation in this temperature range is of interest with respect to investigations of the critical behavior at the surface. Therefore the (110) surface of a 71at%Fe-29at%Al crystal was investigated with low-energy ion scattering. Segregation of Al to the surface was found well below the transition temperature, at 700 K the equilibrium coverage is approximately 94% Al in the first layer and 100% at higher temperatures. In the second atomic layer an Al concentration below the bulk values is found. From the time dependence of the segregation the activation energy for Al diffusion can be estimated. Above 700 K a rearrangement of the Al atoms is observed, indicating that the distance between Al atoms in the top layer is about twice the bulk value. The segregation behavior does not show extraordinary changes when crossing the bulk transition temperature.

引用

页码：1142 / 1146

页数：5

共 11 条

[1]

BUCK TM, 1982, SPRINGER SERIES CHEM, V20, P435

[2] COMPUTER-SIMULATION OF IMPACT-COLLISION ION-SCATTERING SPECTROSCOPY DATA USING HITTING-PROBABILITY INTEGRALS [J].