Investigation of complex magnetic state in La0.8Bi0.2MnO3

We present here the results of a comprehensive study of the DC magnetization, linear and nonlinear AC susceptibility, DC resistivity and Magnetotransport behavior of the La0.8Bi0.2MnO3 polycrystalline manganite to understand its complex magnetic nature. The sample under study is synthesized by a conventional solid state route and is found to crystallize in rhombohedral structure having R3¯c group. A significant irreversibility between zero-field-cooled and field-cooled magnetization data with a broad peak in ZFC is clearly observed. Temperature variation of first and third order AC susceptibilities is in good agreement with Wohlfarth׳s Model for Superparamagnetism (SPM). The analysis of history dependence of DC magnetization, linear and non-linear AC susceptibility provides evidence of SPM like behavior associated along with weak ferromagnetism in the sample at low temperature. The results are supported by the electrical resistivity and Magnetotransport measurements.