Studies on the structural, electrical and magnetic properties of LaCrO3, LaCr0.5Cu0.5O3 and LaCr0.5Fe0.5O3 by sol–gel method

Abstract The structural, electrical and magnetic properties of LaCr 0.5 M 0.5 O 3 (M = Cr 3+ , Cu 2+ and Fe 3+ ) synthesized by a sol–gel technique were studied. The X-ray diffraction pattern shows the structure to be orthorhombic and the size of the particles is around 100 nm as seen from the TEM images. The effects of Cu 2+ and Fe 3+ on the electrical properties of LaCrO 3 were studied using impedance spectroscopy at room temperature (RT). The properties of LaCr 0.5 Cu 0.5 O 3 were studied over a wide range of temperature from RT to 533 K. A maximum conductivity of 1.7 × 10 −3 S cm −1 was observed for LaCr 0.5 Cu 0.5 O 3 at a measured temperature of 533 K. The impedance spectra indicate a negative temperature coefficient of resistance (NTCR) and also imply the conduction is through bulk of the material. The magnetic studies performed using a SQUID magnetometer interpret the antiferromagnetically ordered LaCrO 3 to behave ferromagnetically on the addition of Cu 2+ and Fe 3+ , and the magnetization was found to be enhanced in the LaCr 0.5 Fe 0.5 O 3 .