Exploring the conduction mechanism of multiferroic SrM-BCZT composite

Multiferroic composite of strontium hexaferrite (SrM, SrFe12O19) and barium calcium zirconium titanate (BCZT, Ba0.85Ca0.15Zr0.1Ti0.9O3) have been investigated and the conventional solid-state reaction (SRR) process is utilized to prepare the SrM-xBCZT composite (where x = 0.0, 0.10, 0.20 and 0.30). Diphase stoichiometry was confirmed by the phase analysis, for undoped composition presence of ferromagnetic SrM with complex magnetoplumbite structural phase and hexagonal structural phase with P63/mmc space group was confirmed. Further, doping of BCZT suppressed the secondary phase appeared (Fe2O3) and caused increase in lattice constants. Fourier Transform Infra-Red study revealed the presence of absorption bands of phases. Microstructure analysis suggests the formation of dense composite and confirmed the effect of BCZT as sintering aid. Impedance spectroscopy study suggested two electrical contributions in the microstructure (grain and grain boundary) of charge carriers with short range mobility, while high temperature AC conductivity analysis confirmed double ionized oxygen vacancies conduction. Further, NTCR the negative value of temperature coefficient of resistance and non-Debye type phenomenon is observed, which suggest suitability of these compositions for the heat sensor applications.