Mössbauer effect and electrical properties studies of SmFexMn1−xO3 (x = 0.7, 0.8 and 0.9)

According to the electric properties measurements, it was noted that the conductivity increases two times with increasing the Mn content but the activation energy decreases from 0.34 eV down to 0.22 eV. The sample with x = 0.7 is an electron semiconductor while the other samples display hole conduction. The magnetoresistance MR of the studied samples value is of 10% and has a negative sign at room temperature while a positive sign is obtained with temperature raising.