EPR and Optical Absorption Study of VO2+-Doped Lithium Hydroxylammonium Sulphate |
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Authors: | Ram Kripal Santwana Shukla |
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Institution: | 1. EPR Laboratory, Department of Physics , University of Allahabad , Allahabad, India ram_kripal2001@rediffmail.com;3. EPR Laboratory, Department of Physics , University of Allahabad , Allahabad, India |
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Abstract: | ABSTRACT Single-crystal and powder EPR studies of VO2+-doped lithium hydroxylammonium sulphate (LiNH3OHSO4) were carried out at room temperature. The results indicate the presence of two magnetically inequivalent VO2+ sites. The VO2+ ion takes up a substitutional position in the host lattice. The angular variation of EPR spectra in three mutually perpendicular planes were used to determine the spin Hamiltonian parameters, and the values obtained were the following: For Site 1, gx = 2.0249 ± 0.0002, gy = 1.9698 ± 0.0002, gz = 1.9552 ± 0.0002, Ax = (51 ± 2) × 10?4 cm?1, Ay = (93 ± 2) × 10?4 cm?1, and Az = (165 ± 2) × 10?4 cm?1; and for Site 2, gx = 2.0267 ± 0.0002, gy = 1.9743 ± 0.0002, gz = 1.9213 ± 0.0002, Ax = (40 ± 2) × 10?4 cm?1, Ay = (80 ± 2) × 10?4 cm?1, and Az = (155 ± 2) × 10?4 cm?1. The optical absorption spectrum recorded at room temperature shows four bands. From the optical and EPR data, various molecular coefficients are evaluated, and the nature of bonding in the crystal is discussed. |
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Keywords: | B crystal growth D crystal and ligand fields D optical properties E electron paramagnetic resonance |
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