Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications

Abstract

This study investigates the magnetic properties of Ni0.6Zn0.4Al0.5Fe1.5O4 ceramics as a function of varying temperature. The results show that the sharp change in magnetization at Curie temperatures produces a reasonable magnetic entropy change (ΔS M). The Ni–Zn–Al ferrite is, therefore, predicted to work better than other spinel ferrites with higher efficiencies. Near the second-order transition, the critical exponents are derived from the magnetic entropy change’s field dependency. Their values are close to the mean field model. The reliability of the calculated exponents is confirmed by using scaling theory. The temperature dependence of the dielectric constants shows the presence of phase transitions. In fact, the local disorder provides a frequency that is dependent on relaxor ferroelectric-like behaviors, which is a significant finding in the search for new lead-free relaxor materials. The modified Curie–Weiss law and the Lorentz and Gaussian-type relationships are used to analyze the diffuse phase transition. A correlation between dielectric and magnetic behaviors near the magnetic phase transition temperature (direct observation magnetodielectric effect) is established. Based on these findings, the Ni0.6Zn0.4Al0.5Fe1.5O4 ceramic appears to be a promising candidate for multifunctional device applications.

High-pressure synthesis, spin-glass behaviour, and magnetocaloric effects in FexTi2S4 heideite sulphides

“…Particularly, at 5 T these values reach about 23% of that estimated in pure gadolinium (Gd). 57 On the other hand, our RCP values are close or greater than those recently observed by Massoudi et al 52 for the Ni 0.6 Zn 0.4 Al 0.5 Fe 1.5 O 4 spinel with RCP E 70 J kg À1 (at 5T). Table 3 presents a comparison between the DS max M and RCP values of the Fe x Ti 2 S 4 samples and other reported spinels systems.…”

“…20,51 The ÀDS max M value near the transition temperature can be described as a function of m 0 H by a power-law behaviour as DS max M E aH n , where a and n are the normalization constant and power exponent, respectively. 52 We have plotted ÀDS max M as a function of the magnetic field in Fig. 7d.…”

Effect of frequency on the classical and relaxor ferroelectric behavior of substituted titanate Ba0.7Er0.16Ca0.05Ti0.91Sn0.09O3

“…The Curie–Weiss law, which is defined by eqn (12), characterizes the para-electrical behavior of a classical ferroelectric material. 74–76 …”

Investigation of structural, morphological, and transport properties of a multifunctional Li-ferrite compound

“…Many efforts have been focused during the last years on the preparation of ferrite materials, which has become the object of numerous experimental studies. [1][2][3] Spinel ferrites generally possess a cubic spinel structure with the formula AFe 2 O 4 , where A is usually a divalent metal for satisfying the current manufacturing demands. This structure presents the ideal stoichiometry of spinel ferrite, which fullls the conditions of the cation/anion ratio of 3/4.…”