Effects of Mg Substitution on the Structural with Rietveld Analysis, Magnetic and Magnetocaloric Properties of Ni-Cu-Cd Bulk Ceramics

Abstract

Bulk ceramics with optimized density are highly prioritized over ferrite nanoparticles to fabricate devices for their optimal magnetic saturation, lower coercivity, and anisotropy, enhanced resistance, etc. To achieve such bulk specimen using Ni0.5-yMgyCu0.2Cd0.3Fe2O4 disc samples are sintered at 1423 K keeping the heating and cooling rate at 10 K and 5 K respectively. In due course, structural as well as theoretical Rietveld analysis, optical, and magnetic properties have been analyzed using these bulk samples. XRD has explored structural properties and after that these values have analyzed with the Rietveld refinement procedure and obtained goodness of χ2 (1–2) value and other parameters such as lattice parameters, crystal structures, cation distribution, and maximum entropy mapping. Surface morphology and grain size have examined from the as-grown surface without further polishing and annealing by electron microscopy and revealed a decreasing trend of grain size 6.1 µm to 4.2 µm. UV–Vis spectroscopy characterization ensured optical properties for bulk as well as nanopowders and the band gap has been found in the range of 1.4 to 1.6 eV and is increasing with Mg content. Magnetic hysteresis loop exhibits a less decreasing nature up to y = 0.3 of magnetic saturation along with the Law of Approach to saturation which compiles magnetic anisotropy. The temperature-dependent magnetization curves exhibit a sharp decreasing value (i.e. dM/dT maximum) at Curie point, decreasing from 630 K to 505 K with increasing Mg content. At.3 T magnetic field the changes in relative cooling power value have been found in the range 53.82Jkg-1 to 37.79Jkg-1 which could be considered as potential for magnetocaloric refrigeration.