Comparison of the effect of Cr3+ substituted Co–Cu and Cu–Co nano ferrites on structural, magnetic, DC electrical resistivity, and dielectric properties

• Published in: Journal of materials science. Materials in electronics 2024, Vol.35 (1), p.93, Article 93
• Main Authors: Suryanarayana, B., Varma, P. V. S. K. Phanidhar, Shanmukhi, P. S. V., Kiran, M. Gnana, Murali, N., Mammo, Tulu Wegayehu, Raghavendra, Vemuri, Parajuli, D., Batoo, Khalid Mujasam, Hussain, Sajjad
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystallites; Dielectric properties; Direct current; Doping; Electrical resistivity; Field emission microscopy; Fourier transforms; Grain size; Magnetic properties; Magnetic saturation; Materials Science; Optical and Electronic Materials; Sol-gel processes; Spinel; Substitutes; Trivalent chromium; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-023-11808-6

Cr 3 -substituted Co–Cu (Co 0.7 Cu 0.3 Fe 2−x Cr x O 4 ) and Cu-Co (Cu 0.7 Co 0.3 Fe 2−x Cr x O 4 ) nano ferrite composites were prepared using the sol–gel approach, where x = 0.0, 0.05, 0.1, 0.15, 0.2, and 0.25. We analysed their structural, DC electrical resistivity, magnetic, and dielectric properties comprehensively. X-ray diffraction (XRD) results indicate the formation of a single-phase spinel ferrite structure. The introduction of Cr 3+ ions leads to a reduction in lattice volume and crystallite size. Field emission scanning electron microscopy (FESEM) images reveal non-spherical particles on a uniform surface, with a decrease in grain size as Cr 3+ doping levels increase. The Fourier-transform infrared (FTIR) patterns are consistent with the XRD results, confirming the presence of spinel ferrite. The variation significantly influences the magnetic properties in Cr 3+ doping. The saturation magnetization (Ms) decreases as the Cr 3+ content increases to x = 0.1. Beyond that, it continues to decrease with higher Cr 3+ concentrations. This behavior is attributed to the antiferromagnetic nature of Cr 3+ ions, which do not favour their occupation at the B sites. The DC resistivity increases with higher Cr 3+ concentrations and decreases with rising temperatures, indicating the semiconducting behavior of the ferrites. Furthermore, the loss tangent (tanδ) exhibits an exponential decrease with increasing frequency, pointing to typical Maxwell–Wagner-type dielectric dispersion driven by interfacial polarization.