Charge-disproportionation-induced magnetic glassy behavior in La0.5Ca0.5FeO3-δ -: art. no. 134416

The magnetic properties of La0.5Ca0.5FeO3-delta perovskites with different oxygen vacancy contents were comprehensively investigated by means of x-ray diffraction, Mossbauer spectroscopy, and magnetization measurements. A glassy magnetic behavior was observed by the dc magnetization and ac susceptibility measurements. Around the freezing temperature, a charge disproportionation (CD) phase transition from Fe4+ ions to Fe3+ and Fe5+ ions was detected by Fe-57 Mossbauer spectra. Due to the competition between Fe3+-Fe5+ ferromagnetic interaction and Fe3+-Fe3+ antiferromagnetic interaction, the CD transition from Fe4+ ions to Fe3+ and Fe5+ ions induces the glassy magnetic behavior.