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EPR study of the Jahn-Teller effect of Cu2+ in ZnTiF6·6H20

De, Dilip Kumar and Rubins, R. S. and Black, T. D. (1984) EPR study of the Jahn-Teller effect of Cu2+ in ZnTiF6·6H20. The American Physical Society, 29 (1). pp. 71-78.

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Abstract

The 34-GHz EPR spectrum of Cu2+ in ZnTiF6·6H20 shows a Jahn-Teller effect with a transition from a single-line spectrum at high temperatures to a multiline anisotropic spectrum. The transition temperature on cooling varied with Cu concentration from 172 K for a sample containing 0.2 at.% Cu to roughly 90 K for a 46-at. % Cu sample. For dilute samples, the single-line spectrum was isotropic at 300 K with g =2.223±0.005, but showed axial symmetry about the trigonal axis at 180 K with gj1 =2.226±0.005 and g~ =2.223±0.005. At 4.2 K, a "static" Jahn-Teller effect was observed with six axially symmetric Cu2+ spectra, each with g 11 =2.470±0.005, g1 =2.100±0.005, I A 11 I ~ I 06 X 10- 4 em -I, and I A 1 I ~30 X 10- 4 em - I. The z axis of these spectra was found to lie along the fourfold axes of two cubes with a common [Ill] axis, rotated by 40"±2" with respect to each other about this axis. Analysis of the 4.2-K data leads to the values q~O. 50 for the Ham reduction factor and K~O. 26 for the Fenni contact parameter, with A uA 1 < 0. An activation energy of about 100 cm-1 was deduced from the gradual increase of the anisotropy of the spectrum on cooling in the low-temperature region.

Item Type: Article
Subjects: Q Science > QC Physics
Divisions: Faculty of Engineering, Science and Mathematics > School of Physics
Depositing User: Mrs Patricia Nwokealisi
Date Deposited: 12 Aug 2015 14:27
Last Modified: 12 Aug 2015 14:27
URI: http://eprints.covenantuniversity.edu.ng/id/eprint/5399

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