Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1813987 | Physica B: Condensed Matter | 2009 | 6 Pages |
Abstract
Electron paramagnetic resonance (EPR) study of VO2+ doped zinc potassium phosphate hexahydrate single crystal is carried out. The angular variation of the spectra is studied in the three crystallographic planes. The principal value of spin Hamiltonian parameters g and A and the direction cosines which principal axes make with the crystallographic axes are determined. The observed values are site I: gâ¥=1.9664±0.0002, gâ¥=1.9973±0.0002, Aâ¥=150±2Ã10â4, Aâ¥=60±2Ã10â4 cmâ1; site II: gâ¥=1.9276±0.0002, gâ¥=1.9921±0.0002, Aâ¥=155±2Ã10â4 and Aâ¥=62±2Ã10â4 cmâ1. By comparison of direction cosines of g from EPR with the direction cosines of different bonds obtained from crystal structure data it is ascertained that the VO2+ ion occupies Zn2+ substitutional sites. The optical absorption study of the crystal at room temperature is also carried out. The bands observed in the optical absorption spectrum are attributed to d-d transitions. The EPR results together with the optical data are employed to estimate the molecular orbital (MO) coefficients. These MO coefficients (also called bonding coefficients) are further used to discuss the nature of bonding of VO2+ ion with different ligands in the crystal.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Ram Kripal, Manju Maurya, Manisha Bajpai, Har Govind,