Rietveld refined crystal structure, magnetic, dielectric, and electric properties of Li- substituted Ni–Cu–Zn ferrite and Sm, Dy co-doped BaTiO3 multiferroic composites

Abstract

The conventional solid-state reaction technique is used to fabricate the multiferroic xLi0.1Ni0.3Cu0.1Zn0.4Fe2.1O4(LNCZFO)+(1-x)Ba0.95Sm0.05Ti0.95Dy0.05O3(BSTDO) composites. To determine the ferrite and ferroelectric phases, the Rietveld refinement analysis is used. The excellent fit of experimental diffraction data is confirmed by the low values of reliability factors and the goodness of fit index, and so the crystal structure is perfect. Increasing the LNCZFO phase in the composites causes the formation of more ferrite grains and enhancement of magnetization values. The anisotropy field varies due to compressive stress created by a lattice mismatch between the BSTDO and LNCZFO phases. The dielectric peak shifts to higher temperatures as the ferrite phase increases, indicating that magnetoelectric interaction between the constituent phases exists in composites. At 100 kHz, the diffuseness exponent ranged from 1.01 to 1.79, indicating that a diffuse phase transition (DPT) occurred for some composites. As the ferrite content increases, the DPT effect decreases, resulting a narrower dielectric peak. The small polaron hopping mechanism is responsible for electrical conduction, which followed Jonscher's power law. The magnitude of the angular frequency exponent factor increases with frequency, indicating an increase in charge carrier mobility from long to short range.