Yerima, J. B. and Dikko, A. B. and De, Dilip Kumar (2014) EPR STUDIES OF THE HAMILTONIAN PARAMETERS OF THE SIMULTANEOUS AXIAL AND ORTHORHOMBIC JAHN-TELLER SPECTRA OF Cu2+ IN Cd2(NH4)2(SO4)3 SINGLE CRYSTALS AT DIFFERENT TEMPERATURES. Journal of Engineering and Applied Scientific Research, 6 (1). pp. 62-71.
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Abstract
This paper presents the study of the effective Hamiltonian parameters (g1, g2, A1, A2) and the observed g and A tensors of the derivative axial and orthorhombic Jahn- Teller EPR spectra of Cu2+ in Cd2(NH4)2(SO4)3 single crystals at different temperatures. The variations of these parameters with temperature in the three mutually perpendicular planes of the crystal confirm axial symmetry for T>Tc and orthorhombic symmetry for T<Tc in this system. The simultaneous axial and anisotropic symmetries of the spectra owe their origin to the behaviour of Cu2+ ions in the three JT potential wells because they can undergo reorientation from one well to another or quantum tunnelling among them which depends on temperature, burial height or thickness and energy of the ions. The results show that the components of the activation energy and Fermi-contact parameter increase with temperature while the decrease of the anisotropy parameter (u) is more than it compensates for the slight increase in the effective Hamiltonian parameters g1 and g2 with temperature.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Effective Hamiltonian Parameters, Axial Symmetry, Orthorhombic Symmetry, Temperature, Jahn-Teller Potential Wells. |
| Subjects: | Q Science > Q Science (General) Q Science > QC Physics |
| Divisions: | Faculty of Engineering, Science and Mathematics > School of Physics |
| Depositing User: | Mrs Hannah Akinwumi |
| Date Deposited: | 12 Apr 2015 21:13 |
| Last Modified: | 12 Apr 2015 21:13 |
| URI: | http://eprints.covenantuniversity.edu.ng/id/eprint/4907 |
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