Role of Sr2+ substitution on structural, thermal and conducting behavior of Bi1−xSrxFeO3 (0.40≤x≤0.55)

Bi1−xSrxFeO3 (0.40≤x≤0.55) compounds are synthesized by the solid state reaction method. The as-prepared samples are characterized by X-ray diffraction, a scanning electron microscope, differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), dilatometer and impedance spectrometer. The Rietveld refinement results confirm the tetragonal structure with p4mm symmetry up to x=0.50 followed by the orthorhombic structure with Pmma symmetry for x=0.55. Higher doping (x=0.55) leads to lower crystal symmetry and Curie temperature. Thermal stability is the highest in the x=0.45 sample. The thermal expansion coefficient is ~9.8×10−6/°C. The highest total conductivity observed is ~4.85×10−2 S/cm for the x=0. 50 sample.