ORIENTATIONAL DISORDER IN NI(ND3)6BR2 - A 2-DIMENSIONAL THERMODYNAMIC ROTATION-TRANSLATION MODEL FOR THE DEUTERIUM DISORDER

被引:20
作者
SCHIEBEL, P [1 ]
HOSER, A [1 ]
PRANDL, W [1 ]
HEGER, G [1 ]
机构
[1] CENS, CNRS, CEA, COMMUN LAB, F-91190 GIF SUR YVETTE, FRANCE
来源
ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER | 1990年 / 81卷 / 02期
关键词
D O I
10.1007/BF01309356
中图分类号
O469 [凝聚态物理学];
学科分类号
070205 ;
摘要
The ND3 group in Ni(ND3)6Br2 is orientationally disordered at room temperature: the D3 triangle gives rise to a density distribution with maxima on the corners of a square. We explain this observation as the consequence of a coupled rotational-translational motion of the molecule in a two-dimensional anharmonic single particle potential with tetragonal symmetry. Potential parameters are calculated from experimental data by a least squares procedure. From the total crystal potential of the D3 group we conclude that a combination of center of mass motion and rotation which is possible essentially without an energy barrier, is the basic process observed in quasielastic neutron scattering observations of the jump diffusion. © 1990 Springer-Verlag.
引用
收藏
页码:253 / 258
页数:6
相关论文
共 11 条