Impact of rare earth Tb3+ substitution in cobalt ferrites: Tuning structural, dielectric, magnetic properties and photocatalytic activity

Nanocrystalline CoTb y Fe 2-y O 4 (0 ≤ y ≤ 0.025) ferrites were prepared through the citrate-gel combustion method. X-ray diffraction confirmed the formation of a single-phase spinel structure with crystalline sizes ranging between 19 and 48 nm. The experimental and theoretical lattice parameters correlated well and were found to be ranging between 8.510 and 8.367 Å. SEM images revealed a large aggregation of spherical-shaped nanoparticles with non-uniform shape and distribution. Magnetization measurements revealed the dependance of both M s , Mr, and H C with increasing Tb 3+ content. The evolution of M S and H C upon reducing the measuring temperature indicates the thermal instability of the blocked magnetic moments, which increased for the different compositions. The dielectric properties obtained for CoTb y Fe 2-y O 4 as a function of frequency. The Tb-doped cobalt ferrite catalysts exhibit superior photocatalytic efficiency for crystal violet (CV) degradation as compared to cobalt ferrite nanoferrite catalysts.