Evidence for breaking of the center of symmetry in zero-dimensional H-bonded quantum paraelectric Rb3H(SeO4)2

被引：11

作者：

Gustafsson, T

Ichikawa, M ^{[1
]}

Olovsson, I

机构：

[1] Hokkaido Univ, Div Phys, Grad Sch Sci, Sapporo, Hokkaido 0600810, Japan

[2] Univ Uppsala, Angstrom Lab, S-75121 Uppsala, Sweden

来源：

SOLID STATE COMMUNICATIONS | 2000年 / 115卷 / 09期

关键词：

disordered systems; crystal structure and symmetry; order-disorder effects; phase transitions; neutron scattering;

D O I：

10.1016/S0038-1098(00)00227-1

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

We show by means of single-crystal neutron-scattering that the space group of the quantum paraelectric Rb3H(SeO4)(2) is not centrosymmetric A2/a as accepted so far, but noncentrosymmetric A2. The intensities of the reflections forbidden for the space group A2/a, (h 0 l): h not equal 2n, decrease with decreasing temperature. The refinement of the structure gave a systematically smaller discrepancy values in A2 than in A2/a. This makes it necessary to modify the commonly accepted fact that the space group is A2/a for most members of M3H(XO4)(2)-type crystals. The symmetry breaking is mainly due to the atoms directly connected to the O-H ... O hydrogen-bond system, other parts being substantially unchanged. The possible origin of the temperature dependence of the intensities of the symmetry-breaking reflections is discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.

引用

页码：473 / 476

页数：4

共 14 条

[11]

Makarova I. P., 1986, Soviet Physics - Crystallography, V31, P105

[12] Rb3H(SeO4)(2) at 4K by neutron powder diffraction [J].