RB-87 NMR OF THE STRUCTURAL PHASE-TRANSITION IN RBSCN

被引：12

作者：

BLINC, R ^{[1
]}

SELIGER, J ^{[1
]}

APIH, T ^{[1
]}

DOLINSEK, J ^{[1
]}

FUITH, A ^{[1
]}

SCHRANZ, W ^{[1
]}

WARHANEK, H ^{[1
]}

机构：

[1] UNIV VIENNA,INST EXPTL PHYS,A-1090 VIENNA,AUSTRIA

来源：

PHYSICAL REVIEW B | 1995年 / 52卷 / 02期

关键词：

D O I：

10.1103/PhysRevB.52.833

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The second-order shifts of the Rb-87 1/2 --> - 1/2 NMR transitions have been measured in RbSCN above and below T-c=435 K for crystal rotations around the a, b, and c axes. Whereas below T-c the Rb-87 electric-field gradient (EFG) and chemical shift tensors are compatible with the Rb site symmetry as given by the orthorhombic space group D-2h(ll)(Pbcm), this is not the case for the EFG data above T-c. The results show that the symmetry of the high-temperature tetragonal phase is dynamically broken on the Larmor frequency (10(-8) s) time scale whereas symmetry-breaking terms are averaged out on the ''site'' splitting, domain splitting, and chemical shift tenser (similar or equal to 10(-2)-10(-3) s) time scales. Rb-87 NMR thus allows for an observation of the phase transition in RbSCN in the ''slow motion'' regime where the high-temperature phase is seen to consist of a large number of orthorhombic microdomains with lifetimes longer than 10(-7) s and shorter than 10(-3) s.

引用

页码：833 / 840

页数：8

共 15 条

[1] A REFINEMENT OF CRYSTAL STRUCTURE OF KSCN [J].