Induced magnetism and magnetoelectric coupling in ferroelectric BaTiO3 by Cr-doping synthesized by a facile chemical route

Abstract

Pure phase barium titanate (BTO) and Cr doped BTO have been synthesized by a facile single step metal–organic decomposition (MOD) method. Thermal gravimetric analysis (TGA) is performed on the processed sample to analyse the thermal stability of the compound. A tetragonal to distorted cubic phase transformation of BTO by Cr doping has been confirmed by X-ray diffraction and Raman spectroscopy. Cr doping in BTO reduced the ferroelectric transition temperature from 122 °C to 108 °C. A ferroelectric polarization value of 14.5 μC cm⁻² for pure BTO was obtained, which decreased to 3.7 μC cm⁻² by 1.5 Cr doping. The diamagnetism of BTO partially transformed into ferromagnetic behaviour by Cr-doping at the expense of a decrease in polarization. The magnetoelectric coefficient has been measured by the dynamic ME_B method which was recorded as 13 mV cm⁻¹ Oe⁻¹ for 1.5 Cr : BTO at room temperature. Induced electric polarization has been obtained by applying an external magnetic field due to the local interaction of d electron spins with disordered electric dipoles via oxygen vacancies created by the Cr doping in BaTiO₃. Such materials possess immense potential in low energy consumption for miniaturized device applications in the area of spintronics, sensors and transducers and multistage memory.