Influence of Nb+5 doping in Mn-Zn nanoferrites

Structure and morphology by x-ray diffraction and scanning electron microscopy in Mn0.5−x/2Zn0.5−x/2NbxFe2O4 nano-ferrites, for x, i.e. Nb+5 ranging from 0-0.3 infer cubic and hematite phase structures. Dopant cation complementarily occupy tetrahedral and octahedral sites. Lower x initiates grain formation and further promotes its growth. X-rays and Fourier transform infra-red spectroscopy confirm nanophased structure. Dielectric constant ( r) and loss decreases, while ac resistivity (ρ) increases with x. Lower loss (Tanδ ~ 10−3 to 10−4) and high resistivity (~108 to 109 cm) at 1 MHz ac field indicate preferred utility in high-frequency applications. The influence of grain size is identified by correlative study. Magnetization decreases with doping due to spin canting triggered by diamagnetic dopant. Enhanced field response is attributed to the synthetic route, nanoform, grain size D, spin canting and sintering temperatures. Comparative analysis emphasized the impact of D. Reduced saturation magnetization with x is explained by Yaffet-Kittel angles. Enhanced resistivity by 1-2 orders and less loss vouch for high-frequency applications of Nb+5-doped Mn-Zn nanoferrites as the materials of choice.