Study of Structural, Electrical, and Dielectric Properties of Sm-doped SrMnO3

Abstract

Structural, morphological, electrical, and dielectric properties of the compound SmxSr1-xMnO3, prepared by solid-state reaction and annealed at 650oC for 8 hours, were investigated. X-ray diffraction results showed that the sample has a monoclinic structure with a Sm0.025Sr0.975MnO3 phase. SEM results showed plate-like perovskite grains which were clustered together in 150 nm grains size. The electrical conductivity which was measured by surface-surface contact showed a semiconductor behavior with increasing the ambient temperature. SEM results reflected that there is less orientation and less connectivity of the grains which confirmed the high resistance of the Sm0.025Sr0.975MnO3 sample at room temperature. The sample had two activation energies; 0.791 eV and 0.761 eV. The Impedance, Z(W), AC conductivity, σAC(W.m)-1, relative permittivity, e, and the tangent loss, tan(d), were investigated for the Sm0.025Sr0.975 MnO3 sample. The decrease in sample impedance added to it is used as a dielectric material in the capacitors industry. The AC conductivity had no DC component which depends only on the applied AC only. The decrease of the dielectric constant of the compound was interpreted as the space charge carriers lag after the applied AC field.