Magnetic, dielectric and magnetoelectric properties of CoFe2O4-Bi0.85La0.15FeO3 multiferroic composites

Multiferroic composite nanoparticles of xCoFe(2)O(4)-(1-x) Bi0.85La0.15FeO3 (x = 0.1, 0.2, 0.3 and 0.4) were prepared by a two-step wet chemical procedure, combining co-precipitation and sol-gel techniques. Phase composition, magnetic property, dielectric property and magnetoelectric coupling effect were characterized by XRD, multifunctional magnetic physical testing system, Mossbauer spectroscopy and LCR HiTester. The composites consisted of spinel CoFe2O4 and perovskite Bi0.85La0.15FeO3 phases. Magnetization of the composites was found to increase with increasing CoFe2O4 molar fraction. Both Mossbauer spectroscopic analysis and magnetic measurement confirmed the coupling interaction between the magnetic phase and ferroelectric phase. The higher values of dielectric constant and dielectric loss were observed at lower frequencies in the low frequency range (100 Hz-1 MHz). CoFe2O4 molar fraction in the composites had effect on dielectric resonance in the high frequency range (10-120 MHz). Magnetocapacitance coefficient of the composites was controlled by CoFe2O4 molar fraction at high frequency 100 MHz. (C) 2013 Elsevier B.V. All rights reserved.