MICROSCOPIC APPROACH TO THE QUADRUPOLAR-GLASS PROBLEM

Authors
Citation
Vb. Kokshenev, MICROSCOPIC APPROACH TO THE QUADRUPOLAR-GLASS PROBLEM, Physical review. B, Condensed matter, 53(5), 1996, pp. 2191-2194
Citations number
35
Categorie Soggetti
Physics, Condensed Matter
ISSN journal
01631829
Volume
53
Issue
5
Year of publication
1996
Pages
2191 - 2194
Database
ISI
SICI code
0163-1829(1996)53:5<2191:MATTQP>2.0.ZU;2-G
Abstract
We report results of the microscopic approach to the quadrupolar-glass problem in mixed molecular crystals formed by linear and spherical mo lecules. The temperature-concentration analysis of the orientational o rder parameter derived from NMR spectroscopy data is given on the two- component vector model of site-diluted ortho-para-hydrogen-type mixtur es. Two features of the short-range orientational ordering, characteri stically different from the spin-glass case, namely, incomplete freezi ng and residual ordering, respectively, at low and high temperatures a re discussed. It is established that the first effect is due to spatia l correlated local molecular and reaction fields and the second caused by quadrupolar intrinsic field. A zero-field freezing temperature is estimated taking into account the threshold concentration for quadrupo lar glass formation.