Influence of transition element Os substitution on the structural and electrical features of perovskite structure LaCr_(1- x)Os_xO_3

摘要

This study aims to investigate the electrical properties of LCO compound under Os doping into Cr sites with different substitution levels. The crystalline structure of LaCrO3 and LaCr1-xOsxO3 (LCOO) (x = 0.01, 0.03, 0.05) was inspected with X-ray diffractometer (XRD). Scanning electron microscope (SEM) was utilized to observe the particle/powder morphology. Moreover, the valence states of the elements were investigated by X-ray photoelectron spectroscopy (XPS). The electrical modulus, dielectric constant and conductivity of the LCO and LCOO pellets were detailed by dielectric/impedance spectroscopy studies at different frequencies and temperatures. The temperature dependent power law exponent, calculated through conductivity versus temperature measurements, exhibited that different conduction models are needed to consider for the conductivity mechanism. Furthermore, it has been realized that the activation energies determined from electrical modulus and dc conductivity are close to each other.