Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1811548 | Physica B: Condensed Matter | 2011 | 5 Pages |
Abstract
The local structure distortion and the spin Hamiltonian (SH) parameters, including the zero-field splitting (ZFS) parameter D and the Zeeman g-factors gâ and gâ¥, are theoretically investigated by means of complete diagonalization method (CDM) and the microscopic spin Hamiltonian theory for tetragonal charge compensation CrF5O defect center in Cr3+:KMgF3 crystals. The superposition model (SPM) calculations are carried out to provide the crystal field (CF) parameters. This investigation reveals that the replacement of O2â for Fâ and its induced lattice relaxation Î1(O2â) combined with an inward relaxation of the nearest five fluorine Î2(Fâ) give rise to a strong tetragonal crystal field, which in turn results in the large ZFS and large anisotropic g-factor Îg. The experimental SH parameters D and Îg can be reproduced well by assuming that O2â moves towards the central ion Cr3+ by Î1(O2â)=0.172R0 and the five Fâ ions towards the central ion Cr3+ by Î2(Fâ)=0.022R0. Our approach takes into account the spin-orbit (SO) interaction as well as the spin-spin (SS), spin-other-orbit (SOO), and orbit-orbit (OO) interactions omitted in previous studies. This shows that although the SO interaction is the most important one, the contributions to the SH parameters from other three magnetic interactions are appreciable and should not be omitted, especially for the ZFS parameter D.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Yang Zi-Yuan,