Magnetizations and Mössbauer Spectra of YFe2O4-x

Abstract

Effects of oxygen deficiency on magnetic properties of YFe ₂ O _{4- x} ( x =0.00, 0.031, 0.040, 0.055 and 0.095) have been investigated by magnetization and Mössbauer effect measurements. When x ≧0.055, the compounds show so-called parasitic ferrimagnetism below 210 ∼220 K. When x ≦0.031, on the other hand, they undergo two successive first-order phase transitions at around 230 K and 190 K, without any thermoremanence at any temperature. The compound with x =0.040 exhibits intermediate characteristics. Lattice defects introduced by the oxygen deficiency are considered to play an important role in the disappearance of the first-order transitions and the appearance of the parasitic ferrimagnetism.