Magnetic field control of polarization/capacitance/voltage/resistance through lattice strain in BaTiO3-CoFe2O4 multiferroic nanocomposite

Abstract

Magnetoelectric (ME) nanocomposites is a topic of intensive research due to their superficial potential in spintronic applications. In the present work, the magnetic field controlled electrical polarization is studied in hydrothermally synthesized multiferroic 0.25BaTiO3-0.75CoFe2O4 (BTO-CFO) nanocomposite. This multiferroic heterostructure is combined ferrimagnetic (CFO) with ferroelectric/piezoelectric (BTO) and achieved strain-mediated ME effect, which can effectively mediate magnetic anisotropy. The X-ray diffraction pattern confirmed polycrystalline phases of spinel CFO and tetragonal BTO, for which the compressive lattice strain is made. The microstructural study has evaluated BTO-CFO nanoparticles formation and the value of d-lattice spacing is calculated. The room temperature magnetic hysteresis is arising which depends on CFO inversion degree, and the change in bond-angle/length along A and B-sites. The ferroelectric hysteresis is measured at room temperature, which changed with applied magnetic field, i.e., the phenomenon of reduction in domain wall pinning related with oxygen vacancies and grain boundaries effect. The magnetic field is also influenced impedance spectra to induce magnetoimpedance effect and the positive value of magnetoresistance is obtained. A giant magnetodielectric coefficient up to −27% is obtained at 1 kOe of field. A strain mediated ME coupling enhancement is obtained.