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Magnetization and lattice parameters of Ti substituted Fe-Cr spinels
Vol.8, No.10 7.
ABSTRACTS OF PAPERS TO APPEAR IN
MAGNETIZATION AND LATTICE PARAMETERS OF Ti SUBSTITUTED Fe—’Cr SPINELS E. Schmidbauer, School of Physics, University of Newcastle, Newcastleupon-Tyne, U.K.
Several Ti substituted Fe—Cr oxygen spinels have been synthesized by the usual ceramic sintering technique. Lattice parameters, magnetic properties and cation distributions have been investigated. On substituting Ti, the Fe—Cr spinels prepared remained cubic at room temperature, the lattice parameters increasing with rising Ti concentration whereas the Curie temperatures decreased. For some compositions the curveshumps between the magnetization—temperature Curie points and 1850 C exhibit at high Ti contents (H = 14.5 koe). Possible mechanisms to explain this fact are taken into consideration. In addition, the origin of a thermal hysteresis in the magnetization temperature curves found close to the Curie point is discussed. —
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8.
J. PHYS.
CHEM. SOLIDS
iii
ABSORPTION SPECTRUM OF COBALT FLUOSILICATE HEXAHYDRATE J.P. Srivastava, Department of Physics, Indian Institute of Technology, Kanpur, India
Absorption spectrum of cobalt fluosilicate has been measured at room (-v.~300°K) and liquid nitrogen (-‘.. 80°K)temperatures. At low temperatures 4T2 0(F) and 27’ 19(H) bands are found to split. An attempt has been made to explain these splittings on the basis lower symmetry fields present in the crystal. The observed band positions have been fitted with the parameters B, C and Dq. The values of these parameters are found to 1. be B = 870 cm’, C= 4.5B and Dq = 965 cm Received 10 March 1970
ABSTRACTS OF PAPERS TO APPEAR IN
MAGNETIZATION AND LATTICE PARAMETERS OF Ti SUBSTITUTED Fe—’Cr SPINELS E. Schmidbauer, School of Physics, University of Newcastle, Newcastleupon-Tyne, U.K.
Several Ti substituted Fe—Cr oxygen spinels have been synthesized by the usual ceramic sintering technique. Lattice parameters, magnetic properties and cation distributions have been investigated. On substituting Ti, the Fe—Cr spinels prepared remained cubic at room temperature, the lattice parameters increasing with rising Ti concentration whereas the Curie temperatures decreased. For some compositions the curveshumps between the magnetization—temperature Curie points and 1850 C exhibit at high Ti contents (H = 14.5 koe). Possible mechanisms to explain this fact are taken into consideration. In addition, the origin of a thermal hysteresis in the magnetization temperature curves found close to the Curie point is discussed. —
—
8.
J. PHYS.
CHEM. SOLIDS
iii
ABSORPTION SPECTRUM OF COBALT FLUOSILICATE HEXAHYDRATE J.P. Srivastava, Department of Physics, Indian Institute of Technology, Kanpur, India
Absorption spectrum of cobalt fluosilicate has been measured at room (-v.~300°K) and liquid nitrogen (-‘.. 80°K)temperatures. At low temperatures 4T2 0(F) and 27’ 19(H) bands are found to split. An attempt has been made to explain these splittings on the basis lower symmetry fields present in the crystal. The observed band positions have been fitted with the parameters B, C and Dq. The values of these parameters are found to 1. be B = 870 cm’, C= 4.5B and Dq = 965 cm Received 10 March 1970