A comparative structural, thermal and electrical study of Ca2 +, Sr2 + substituted BiMnO3

• Bi1 -xAxMnO3 (A = Sr, Ca;0.40 ≤ x ≤ 0.55) was synthesized by solid state reaction method.
• Crystal symmetry of samples is confirmed by Rietveld refinement.
• Bi1 -xSrxMnO3 system shows higher conductivity as compared to Bi1 -xCaxMnO3.
• Bi0.50Sr0.50MnO3 exhibit highest conductivity of ~ 180S/cm.

Bi1 -xAxMnO3 (A = Sr, Ca; 0.40 ≤ x ≤ 0.55) systems have been synthesized by solid state reaction method to investigate the effect of two different cations substitution in place of Bi3 +. All samples are monophasic as observed in X-ray diffraction. The Bi1 -xSrxMnO3 shows the tetragonal symmetry whereas, Bi1 -xCaxMnO3 shows orthorhombic as confirmed by Rietveld refinement. The Bi1 -xSrxMnO3 system shows higher conductivity as compared to Bi1 -xCaxMnO3. Bi0.50Sr0.50MnO3 exhibits highest conductivity of 180 S/cm at 790 °C which can be attributed to its higher specific free volume and uniform grain size with better distribution in entire structure. Sr2 + doped system has lower thermal expansion coefficient as compared to Ca2 + doped system.