Mössbauer hyperfine interactions in natural wolframites
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Powdered samples of Indian Natural Wolframites, (FexMn1−x) WO4 with x=0.95 to 0.41, obtained from seven different locations of two quartz-wolframite deposits of Degana and Sirohi in Rajasthan, have been investigated by Mössbauer spectroscopy down to 20K and magnetic susceptibility down to 77K. The Mössbauer spectra from 300K to 30K clearly indicate multiple sites which is at variance with the reported work. Below 50K a weak magnetic interaction with Hint∼45Koe is observed. The spectra above transition temperature are resolved in three doublets and explained on the basis of reported crystal structure. The values of isomer shift, quadrupole splitting and magnetic hyperfine field have been attributed to high spin ferrous ions with octahedral symmetry. Relatively small value of Q.S. (∼1.5 mm/sec. at 300K) indicate a strong contribution of the lattice term to the electric field gradient.
KeywordsMagnetic Susceptibility Powdered Sample Field Gradient Multiple Site Isomer Shift
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- 1.L.C. Hsu, Amer. Mineral. 61 (1976) 944.Google Scholar
- 6.H. Weitzel, Dissertation, University of Tubingen, Germany (1969).Google Scholar
- 7.H. Weitzel, Jahrb. Miner. Abh. 113 (1970) 13.Google Scholar
- 14.A. Sasaki, J. Mineral. 2 (1959) 375Google Scholar
- 15.Ch. Klein and R. Geller, J. Phys. (Paris) C-6 (1974) 589.Google Scholar
- 17.R. Caruba, A. Baumer, R. Guillen, J.R. Regnard, Bull. Mineral 105 (1982) 246.Google Scholar
- 19.V.I. Goldanskii, G.M. Gorodinskii, S.V. Karyagin, L.A. Korytko, L.M. Krizhanskii, E.F. Makarov, I.P. Suzdalev and V.V. Khrapov, Doklady Akad. Nauk S.S.S.R. 147 (1962) 127.Google Scholar
- 20.T. Ericsson, R. Wappling, J. Phys. (Paris) C6 (1976) 719.Google Scholar