Evaluation of temperature-dependent studies of holmium-doped Cu–Co spinel ferrites-based graphene composites
摘要
Graphene-decorated spinel composites are emerging as a novel material with potential applications in flexible electronic devices and contemporary energy storage systems due to their robust mechanical properties, flexibility, cost-effectiveness, and lightweight nature. In the present study, the composite of Cu0.3Co0.7Ho0.1Fe1.9O4 with 7.5% graphene has been synthesized through the sol–gel auto-combustion process. The X-ray diffraction analysis proves the formation of a single-phase face-centered cubic spinel structure. The lattice parameter is found to be 8.364 Å at the temperature of 600 °C and 8.330 Å at 900 °C. In the same way, the crystallite size decreases from 10.476 nm at 600 °C to 7.749 nm at 900 °C. The scanning electron microscope images indicate a uniform distribution of the grains with no significant alteration in the grain size with an increase in sintering temperature. Raman Spectra detect five different vibrational modes, where the A1g and Eg modes are related to tetrahedral Fe–O stretching and O2− bending vibration, and the T2g modes are the vibrations of the octahedral sites. Vibrational bands found at 620–710 cm−1 and 410–620 cm−1 identify the A-site and B-site metal ions, respectively. Moreover, the ferrite composite that has been sintered at 800 °C has minimal dielectric losses and a minimal activation energy of 0.46 eV. Higher temperatures increase AC conductivity, particularly at high frequencies. Furthermore, the electrical conductivity of the studied composite changed between 2.69 × 10–11 and 0.012 × 10–11 Ω−1 cm−1. These characteristics underscore the potential of the studied composite for next-generation electronic devices.