International Journal of Applied Research
Vol. 1, Issue 13, Part F (2015)
To study of epr parameters for MN2+ in the fluoroperovskites ABF3
Arvinder Singh and Dr. Manoj S Shekhawat
The electron paramagnetic resonance (EPR) parameters (g factor, the hyperfine structure constant A and the super hyperfine parameters A’ and B’) for Mn2+ in the fluoroperovskites ABF3 (A =K and Cs; B = Zn, Mg, Cd and Ca) are theoretically investigated from the perturbation formulas of these parameters for a 3d5ion under ideal octahedra. In the above treatments, not only the crystal-field mechanism but also the charge transfer mechanism is considered uniformly on the basis of the cluster approach. The theoretical EPR parameters are in good agreement with the experimental data. The charge transfer contribution to the g-shift g ( g−gs, where gs≈2.0023 is the spin-only value) is opposite (positive) in sign and comparable in magnitude to the crystal-field one. Nevertheless, the charge transfer contribution to the hyperfine structure constant shows the same sign and about 10% that of the crystal-field one. So, the conventional argument that the charge transfer contributions to the zero-field splittings are negligible for 3d5 ions under low symmetrically distorted fluorine octahedra is proved no longer valid for the ganalysis of ABF3:Mn2+ in view of the dominant second-order charge transfer perturbation terms. The unpaired spin densities of the fluorine 2s, 2p and 2p orbitals are determined from the quantitativedependences upon the related molecular orbital coefficients, rather than obtained by fitting the observed super hyperfine parameters in the previous works.
How to cite this article:
Arvinder Singh and Dr. Manoj S Shekhawat. To study of epr parameters for MN2+ in the fluoroperovskites ABF3. International Journal of Applied Research. 2015; 1(13): 397-403.