Magnetization Measurements and ⁵⁷Fe Mössbauer Studies of LaNi_1-xFe_xO₃ (0.0≤x≤0.2)

Abstract

Magnetization measurements and 57 Fe Mössbauer study of LaNi 1- x Fe x O 3 (0≤ x ≤0.2) were made. Temperature independent susceptibility of LaNiO 3 increases with Fe substitution. At high temperatures, the increment of the susceptibility due to Fe, obeys the Curie-Weiss law, with µ eff of 4 µ B /Fe. At low temperatures, a small amount of remanent magnetization appears and the Mössbauer spectra show hyperfine magnetic splittings. The value of H hf (≃400 kOe) extrapolated to 0 K and that of I S (≃0.34 mm/s) are considerably smaller than the typical ones for Fe 3+ in octahedral sites in ionic oxides. The magnetically ordered phase at low temperatures seems to be a spin-glass or a mictomagnet in which Fe 3+ moments are frozen, coupled by long range exchange interactions in addition to the nearest neighbor superexchange interactions.