Structural and physical properties of microwave synthesized orthorhombic perovskite erbium chromite ErCrO3

• Published in: Journal of the European Ceramic Society Vol. 32; no. 3; pp. 611 - 618
• Main Authors: Prado-Gonjal, Jesús, Schmidt, Rainer, Ávila, David, Amador, Ulises, Morán, Emilio
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2012
• Subjects: A. Microwave processing; B. Microstructure-final; B. X-ray methods; C. Dielectric properties; C. Magnetic properties; Ceramics; Chromite; Chromites; Dielectrics; Electrodes; Grain boundaries; Metal nitrates; Microwaves; Rare earth metals; B. X-ray methods; Chromites; C. Dielectric properties; C. Magnetic properties; A. Microwave processing; B. Microstructure-final
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2011.10.002

Rare-earth chromite ErCrO3 powder was synthesized from metal nitrate precursors using microwave synthesis. (Micro-) structural characterizations were performed using X-ray diffraction, Rietveld refinement, High Resolution Transmission Electron Microscopy and Electron Micro-Diffraction. Magnetization vs. temperature measurements revealed anti-ferromagnetism with TNeel≈135K. An anti-ferrimagnetic moment of ≈0.4μB was determined from magnetization vs. applied field measurements. Temperature dependent impedance spectroscopy (IS) indicated 3 dielectric relaxation processes: electrode interface, grain boundary and bulk. The intrinsic bulk activation energy was found to be 0.27eV and the dielectric permittivity ɛr was ≈23 in excellent agreement with Clausius–Mossotti predictions and showed no perceptible temperature dependence. This and the low ɛr value suggested that ErCrO3 is a dielectric rather than ferroelectric compound. IS measurements with applied dc bias revealed the signs of an unconventional type of Schottky barrier at the metallic Au electrode/ceramic ErCrO3 interface.