Mössbauer and neutron‐diffraction studies of LaCo 0.42 Fe 0.58 O 3– d

Mössbauer, neutron powder diffraction and magnetization measurements have been performed for the LaCo 0.42 Fe 0.58 O 3– d compounds in the temperature range 4.2 K < T < 400 K. It was found that a stoichiometric compound has a canted G‐type antiferromagnetic structure with T N ∼ 380 K and magnetic moment of 2.3 µ B per formula unit. Combined Mössbauer and neutron‐diffraction data give evidence that only Fe 3+ ions are in the magnetically ordered state, whereas Co 3+ ones are in the nonmagnetic low‐spin state and do not participate actively in the magnetic interactions. The oxygen loss leads to the reduction of Co ions down to the 2+ valence state keeping Fe ions in the 3+ valence state. At the same time the T N temperature increases and the weak ferromagnetic component is suppressed. Newly generated strong antiferromagnetic interactions Co 2+ –O–Fe 3+ arise. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)