Studies on physicochemical properties of pure and iron substituted chromium niobates, Cr1-xFexNbO4 (x=0, 0.2, 0.4, 0.6)

Abstract Pristine and iron substituted chromium niobates (Cr 1−x Fe x NbO 4 with x = 0, 0.2, 0.4 and 0.6) are prepared by solid-state synthesis and phase characterised by X-ray diffraction. Microstructure is determined using scanning electron microscope and micro-chemical analysis is performed by energy dispersive X-ray analysis (EDX). The current-voltage characteristics are studied in the temperature range of 423–723 K. The electrical conductivity of sintered pellets is measured by impedance spectroscopy. Temperature dependent magnetization studies are performed using vibrating sample magnetometer (VSM) and room temperature Bohr magneton number is calculated from the magnetic susceptibility data. The conductivity is passed through a minimum at x = 0.2 in Cr 1−x Fe x NbO 4 for x = 0–0.6. X-ray photoelectron spectroscopic studies revealed the surface non-stoichiometry in these compositions.