Magnetic properties of perovskite Ca1−xSrxFeO3

We synthesized Ca1−xSrxFeO3 containing tetravalent iron Fe4+ with high valence by low temperature heat treatment along with ozone oxidization. We investigated the magnetic properties of perovskite Ca1−xSrxFeO3. The charge disproportionation transition temperature (TCD) of Ca1−xSrxFeO3 was observed from x = 0.0 to 0.6 in the magnetic susceptibility measurements. The decrease in TCD occurs is attributed to deformation of the crystal structure. The metamagnetic transitions with hysteresis were observed in the magnetization curves of all the compositions. The metamagnetic behavior is due to helical magnetism, which means that there are intermediate stable states before magnetization is saturated. In the Sr-rich region with x = 0.8 and 1.0, the saturation magnetization shows forced ferromagnetic order with a value of ∼3.2 μB at high magnetic field, H ∼ 60 T.