Dielectric and electrocaloric properties of BCTZ composite with cobalt zinc ferrite nanoparticles.

• Dielectric and electrocaloric properties of BCTZ-(Co,Zn)Fe 2 O 4 composite are reported. • ϵ*(102–106 Hz) at different t unfolds domain wall and carrier polarization relaxations. • ∆S dip of the composites increases with x. • 'low tan δ and non-leaky PE loop' is observed in the BCTZ-CZF composite. Dielectric and electrocaloric properties of a multiferroic composite constituted from Ba 0.85 Ca 0.15 Ti 0.9 Zr 0.1 O 3 (BCTZ) and Co 0.4 Zn 0.6 Fe 2 O 4 (CZF), chosen for their closely related transition temperatures, are reported. Dielectric characteristics of the composites in the 1 kHz − 10 MHz angular frequency range are described by two Cole-Cole relaxation models (domain wall and charge carrier) whereas for frequency <1 kHz, it is explained by Maxwell-Wagner type interfacial polarization using Jonscher power law. The effect of CZF phase on the dipolar mechanisms as a function of CZF mole fraction and the temperature are discussed. The electrocaloric property of the composites is estimated indirectly by Maxwell thermodynamic relation. [Display omitted] [ABSTRACT FROM AUTHOR]