Journal of Materials Science, Vol.48, No.21, 7629-7634, 2013
Heat capacity, thermopower and magnetoresistance effects in multiferroic La0.5Bi0.5Mn0.5Fe0.5O3
We have carried out systematic investigations in perovskite multiferroic La0.5Bi0.5Mn0.5Fe0.5O3 by means of X-ray diffraction, magnetisation, electrical resistivity, thermoelectric and heat capacity measurements. The magnetic behaviour of this composition is rather complex, though the magnetisation curve seems to be like a weak ferromagnetic material. However, there is no clear evidence of lambda-anomaly in the heat capacity data down to 2 K, yet this behaviour corroborate the trends of semiconducting silicon below room temperature. The sensitivity of magnetic behaviour to the iron-manganese ratio is also demonstrated. In presence of an external field of 7 T, it exhibits a magnetoresistance of -5 % at 130 K. The thermoelectric value increases linearly with decreasing temperature, and at room temperature the value is +85 mu V/K, which is associated with the p-type polaronic conductivity.