Effect of calcining temperature on the microstructure and magnetic properties of CuFeO₂ multiferroic ceramic

Abstract

Multiferroic ceramic CuFeO 2 has been successfully fabricated by traditional solid-state reaction method under different calcining temperatures. X-ray powder diffraction results show that a higher calcining temperature is beneficial to form single delafossite phase with a hexahedron crystal structure. Raman and scanning electron microscopy results indicate that the proper calcining temperature is favourable to enhance the polarisation strength, grain size and density of samples. Magnetic properties results reveal that all samples exhibit two successive magnetic transitions with decreasing temperature, the corresponding magnetic transition temperature T N1 and T N2 are independent on calcining temperature. It is also found that the magnetic state of all samples at T = 10 and 13 K is weak ferromagnetic or ferrimagnetic state but not the antiferromagnetic state in theory. The value of magnetic susceptibility and saturation magnetisation are effectively enhanced by changing calcining temperature. The relationship between the microstructure and magnetic properties of CuFeO 2 system is discussed in this paper.