NEAR-SURFACE X-RAY CRITICAL SCATTERING FROM A NH4BR (1(1)OVER-BAR-0) SURFACE

被引：20

作者：

BURANDT, B ^{[1
]}

PRESS, W ^{[1
]}

HAUSSUHL, S ^{[1
]}

机构：

[1] UNIV COLOGNE,INST KRISTALLOG,W-5000 COLOGNE,GERMANY

来源：

PHYSICAL REVIEW LETTERS | 1993年 / 71卷 / 08期

关键词：

D O I：

10.1103/PhysRevLett.71.1188

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present the first observations of near-surface critical phenomena of a phase transition in a molecular solid showing both an order-disorder and a strong displacive component. The surface x-ray scattering experiments were performed on an NH4Br single crystal (T(c) = 235 K). For the order parameter they show a crossover from a power law with the bulk critical exponent beta = 0.3 +/- 0.05 to a surface behavior with exponent beta1 = 0.8 +/- 0.1. From the diffuse intensity we have determined the critical exponents eta(parallel-to) = 1.3 +/- 0.15, nu = 0.5 +/- 0.15 and the correlation length xi0+ = 4 +/- 0.5 angstrom.

引用

页码：1188 / 1191

页数：4

共 16 条

[1] SURFACE MAGNETISM OF NI(100) NEAR THE CRITICAL REGION BY SPIN-POLARIZED ELECTRON-SCATTERING [J].