Structural, electrical, dielectric and optical properties of PrCrO3 ortho-chromite

Abstract The structural, optical, electrical and dielectric properties of PrCrO3 perovskite prepared through the sol-gel method were investigated in details. Our compound was characterized by X-ray powder diffraction (XRD) at room temperature. It has been demonstrated that it crystallizes in the orthorhombic system with Pnma space group. The infrared (IR) spectrum highlighted a set of absorption peaks that can be attributed to the O–Cr–O and Cr–O vibrations. The reflectance spectrum, determined by UV–Vis absorption spectrometry, provides the direct optical band gap Eg = 3.24eV of the studied structure. The electrical and dielectric study was carried out by impedance spectroscopy (IS) in a wide frequency (40–106Hz) and at a temperature varying from 160 to 440 K. DC conductivity measurements indicate that PrCrO3 discloses a semiconductor behavior with a semiconductor to metal transition estimated at TMS = 400 K. AC conductivity follows Jonscher's equation. Nyquist plots reveal the existence of two well separated relaxation contributions related to the grains at high frequencies and grain boundaries at low frequencies. Furthermore, colossal dielectric permittivities were detected, showing the importance of this compound in electronic devices.