Investigation of the garnet-perovskite transition in Nd doped YIG by means of magnetic disaccommodation

Abstract

The garnet-perovskite transition is studied in this work with magnetic disaccommodation on polycrystalline Nd doped YIG samples Y3-xNdxFe5O12 (0 < x < 2.5). A very different behaviour with the sintering atmosphere is observed. The results of magnetic disaccommodation for samples sintered in air reveal that the low temperature peak of YIG at 120 K disappear and another peak emerge at 300 K with x = 2.0, when the solubility limit is surpassed and the compound contains secondary perovskite phase and magnetite. For CO2 sintered samples, the process at 120 K exhibit magnetic accommodation features (i.e. negative disaccommodation), and vanishes with increasing Nd substitution, together with the appearance of the 300 K peak associated with the garnet-perovskite transition which takes place with x ≈ 1.4 doping. Thermal evolution of magnetic permeability and X-ray diffraction support the behaviour observed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)