Thermally activated variations in conductivity and activation energy in SrMnO_3

摘要

Abstract In this paper, we present a series of strontium manganite samples, synthesized using an efficient sol–gel based auto-combustion route by optimizing the calcination temperature and time. X-ray diffraction revealed the formation of pure phase hexagonal perovskite structure in the sample calcined at 1000 °C for 4 h. Tangent loss and loss factor versus frequency plots demonstrate total losses present in the material which are important parameters in determining immunity level of the materials for magneto-electric coupling potentially viable for non-volatile ferroelectric random access memories. Frequency dependent ac conductivity at different temperatures indicates that the conduction process is thermally activated. Trend of ac conductivity exhibits frequency independent and dependent regions. Correlation of the ac and dc conductivities along with hopping mechanism has also been probed. The activation energy has been calculated from an Arrhenius plot of dc conductivity and relaxation frequency.