Electric field properties at cationic sites in normal, incommensurate and commensurate K2ZnCl4 crystals

Citation
Mn. Grecu et S. Constantinescu, Electric field properties at cationic sites in normal, incommensurate and commensurate K2ZnCl4 crystals, APPL MAGN R, 16(3), 1999, pp. 373-382
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
APPLIED MAGNETIC RESONANCE
ISSN journal
0937-9347 → ACNP
Volume
16
Issue
3
Year of publication
1999
Pages
373 - 382
Database
ISI
SICI code
0937-9347(1999)16:3<373:EFPACS>2.0.ZU;2-M
Abstract
The local electric properties at K and Zn sites in the normal, incommensura te and commensurate phases of K2ZnCl4, as derived from a numerical computat ion of the lattice contributions to the electric potential V(r), electric f ield intensity E(r) and electric field gradient tensor V-alpha beta(r) are reported. The numerical data obtained at each cationic position were correl ated with the experimental K-39 NMR, Cu2+ and Mn2+ EPR and Fe-57 Mossbauer results in pure and doped K2ZnCl4. A proportionality between crystal field and zero-field splitting was taken into account for Mn2+, whereas for K+, C u2+ and Fe3+ ions the electric field gradient is directly related to the cr ystal field parameter. By this comparison, on computations done in the ioni c fractional charge and relaxed lattice approximations, the insertion of pr obe-species of iron, copper and manganese ions on off-center Zn sites is pr oposed. The K-39 electric field gradient tensor calculations in the incomme nsurate phase fit well with the NMR data reported recently.