Open AccessNMR STUDIES ON THE LOW TEMPERATURE PHASE TRANSITION IN LiKSO4
Author(s) -
Qingxi Meng,
Cao Qi-juan
Publication year - 1982
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.31.1405
Subject(s) - electric field gradient , principal axis theorem , quadrupole , phase transition , asymmetry , phase (matter) , materials science , condensed matter physics , symmetry (geometry) , crystal (programming language) , coupling (piping) , orientation (vector space) , nuclear magnetic resonance , single crystal , electric field , physics , atomic physics , quantum mechanics , geometry , mathematics , computer science , metallurgy , programming language
The dependence of 7Li NMR spectrum in LiKO4 on temperature and crystal orientation has been studied. It is confirmed that there is a structural phase transition at Tc = 195K below which the crystal symmetry is lower than P31c and its unit cell contains at least six molecular formulae. There is no evidence of the existence of an incommensurate phase. At 181K the quadrupole coupling conatant is 38.9 kHz, the asymmetry parameter η = 0.46, and the principal direction z of the electric field gradient makes an angle of 11.6° with the original c axis.