Modulation of magnetic and dielectric property of LaFeO3 by simultaneous doping with Ca2+ and Co2+-ions
Résumé
Structural, magnetic and dielectric properties of Ca and Co co-doped LaFeO3 [La0.9Ca0.1Fe0.9Co0.1O3, LCFCO] sample are investigated. Nanoparticles of pure LaFeO3 (LFO) are prepared using sol-gel wet chemical method. Here, Ca2+ and Co2+ dopants are chosen to improve the dielectric and magnetic properties of LFO, respectively. The refinement of X-ray diffraction patterns is consistent with the formation of distorted orthorhombic phase of LFO. The analysis of Raman and Mössbauer spectra allow to extract different structural and magnetic information. The observed field dependency of magnetization confirms the introduction of ferromagnetism in the antiferromagnetic structure of LFO due to the doping. Thermal variation of the magnetization suggests a strong domination of ferromagnetic part over antiferromagnetic at low temperatures, which is not found in LFO. The temperature variation of the dielectric constant gives rise the dielectric transition temperature of the doped sample. The dielectric spectroscopy of the samples is found to follow the Cole-Cole relaxation with improved dielectric and magneto-dielectric property of the doped sample.