Mossbauer and neutron-diffraction studies of LaCo0.42Fe0.58O3- d

Mossbauer, neutron powder diffraction and magnetization measurements have been performed for the LaCo0.42Fe0.58O3–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 TN ∼ 380 K and magnetic moment of 2.3µB per formula unit. Combined Mossbauer and neutron-diffraction data give evidence that only Fe3+ ions are in the magnetically ordered state, whereas Co3+ 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 TN temperature increases and the weak ferromagnetic component is suppressed. Newly generated strong antiferromagnetic interactions Co2+–O–Fe3+ arise. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)