Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1816230 | Physica B: Condensed Matter | 2007 | 7 Pages |
Abstract
EPR study of Mn2+-doped zinc ammonium phosphate hexahydrate (ZAPH) is done at room temperature. The Mn2+ spin Hamiltonian parameters are evaluated employing a large number of resonant line positions observed for different orientations of the external magnetic field. The evaluated value of g-factor is 1.9527±0.0002 and the values of other parameters D, E, a, A and B (in 10â4 cmâ1) are, 175±2, 58±2, 10±1, 92±2 and 86±2, respectively. The optical absorption study of the crystal is also done. The observed bands are assigned as transitions from the 6A1g(S) ground state to various excited quartet levels of Mn2+ ion in a cubic crystal field. These bands are fitted with four parameters: inter-electronic repulsion parameters (B and C), cubic crystal field splitting parameter (Dq), and Tree's correction (α). The values obtained for the parameters are B=917, C=2254, Dq=756 and α=76 cmâ1. From the data obtained the surrounding crystal field and the nature of metal-ligand bonding are discussed. The considerable decrease in the values of B and C from their free ion values indicates the existence of a fair amount of covalent bonding between the central metal ion and the ligand. On the basis of the deviations Îg=gâ2.0023, the transfer of electrons to or from the central metal ion for bond formation is ascertained.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Ram Kripal, Har Govind, S.K. Gupta, Manju Arora,