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

The structural, electrical and magnetic properties of LaCr0.5M0.5O3 (M = Cr3+, Cu2+ and Fe3+) 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 Cu2+ and Fe3+ on the electrical properties of LaCrO3 were studied using impedance spectroscopy at room temperature (RT). The properties of LaCr0.5Cu0.5O3 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 LaCr0.5Cu0.5O3 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 LaCrO3 to behave ferromagnetically on the addition of Cu2+ and Fe3+, and the magnetization was found to be enhanced in the LaCr0.5Fe0.5O3.

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► LaCr0.5M0.5O3 (M = Cr3+, Cu2+ and Fe3+) was synthesized by simple sol–gel technique with subsequent heat treatment.
► The compound formation temperature was optimized through XRD analysis.
► The effects of Cu2+ and Fe3+ on the electrical properties of LaCrO3 were studied using impedance spectroscopy.
► The temperature dependence of electrical conductivity was discussed for LaCr0.5Cu0.5O3.
► The magnetization was found to be enhanced in the LaCr0.5Fe0.5O3.