Structural, magnetic and magneto-transport properties of Bi0.7-xLaxSr0.3MnO3 manganites

Abstract In the present study, the structural, magnetic, and magneto-transport properties of Bi0.7-xLaxSr0.3MnO3 manganites have been investigated. Systematic replacement of Bi3+ with La3+, reduces the distortion in the crystal structure and the system transforms from antiferromagnetic insulating (AFMI) state to ferromagnetic metallic (FMM) state. For partial doping of La3+, the system shows a low temperature drop in ZFC which could be attributed to the spin-glass transition in addition to the antiferromagnetic ordering. dc electrical resistivity describes the insulating behavior of the system which is consistent with antiferromagnetic (AFM) ground state for partial La3+ doping. The activation energy estimated from the small polaron hopping model, shows a systematic decrease as a function of La3+ concentration. The observed results could be explained by considering the dilution of 6s lone pair character of Bi3+ with La3+ doping.