Magnetic and electrical properties of lanthanum substituted yttrium iron garnets
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Polycrystalline yttrium lanthanum iron garnets (Y3LaxFe5-xO12) with varying La substitution (0 ≤ x ≤ 0.5) have been prepared in the pellet form, and studied by X-ray diffraction, magnetization, a.c. susceptibility and electrical resistivity measurements. The lattice constants are determined and the applicability of Vegard’s law has been tested. The saturation magnetization (4 πMS) decreases very slowly almost linearly with increasing x from x = 0.0–0.5 indicating minimal reduction in ferrimagnetism and least magnetic loss. Variation of saturation magnetic moment per formula unit at 300 K with x can be explained satisfactorily assuming the collinear spin-ordering model. The Curie temperature (Tc) reduces very slowly with increasing x, which is consistent with the observed decrease in 4 πMS with x. The activation energy (E) decreases very slowly with increasing x for x > 0.1.
KeywordsSaturation Magnetization Yttrium Iron Garnet Electrical Resistivity Measurement Yttrium Iron Collinear Spin
The authors are thankful to Professor R. G. Kulkarni, Dept. of physics, Shivaji University, Kolhapur, India for his valuable suggestion and fruitful discussion. The author is also thankful to USIC, Shivaji University, Kolhapur for providing X-ray diffractometric charts.
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