Magnetic properties of perovskite Ca1−xSrxFeO3.

We synthesized Ca_1−xSr_xFeO₃ containing tetravalent iron Fe⁴⁺ with high valence by low temperature heat treatment along with ozone oxidization. We investigated the magnetic properties of perovskite Ca_1−xSr_xFeO₃. The charge disproportionation transition temperature (T_CD) of Ca_1−xSr_xFeO₃ was observed from x = 0.0 to 0.6 in the magnetic susceptibility measurements. The decrease in T_CD 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 μ_B at high magnetic field, H ∼ 60 T. [ABSTRACT FROM AUTHOR]