Structural, magnetic and ESR studies of Y3AlxFe5−xO12 (0.0≤x≤1.2) nanoparticles synthesized by a sol-gel method

Fabrication of garnet nanoparticles as per the device requirement is still a big challenge and technological problem. In order to fulfil the requirement of microwave device engineer, we have synthesized nanoparticles of aluminium (Al) doped YIG by a citrate sol-gel method using metal nitrates, citric acid, ethylene glycol and ammonia. The XRD and FTIR study confirmed the single phase cubic garnet structure. The crystallite size was increased from 55 to 60 nm and the particle size decreased from 87 nm to 59 nm suggesting a departure from multi-domain to single-domain particles. The saturation magnetization (Ms) decreased from 21.06 emu/g for x = 0.0 to 1.06 emu/g for sample x = 1.2. The peak to peak linewidth (ΔHp) values increased from 110 G to 620 G due to a reduction in superexchange interaction by Al ions. The properties of Al-YIG obtained in this study will be useful for phase shifter and circulator applications. •The lattice constant, d-spacing, X-ray density & saturation magnetization decreased with increasing aluminium concentration.•Elongated and smaller particles increased shape anisotropy which in turn increased the coercivity of the samples with increasing aluminium content.•As aluminium content increased, the peak to peak linewidth also increased due to weakening of superexchange interaction.•The decrease in g-effective values is observed due to the dominance of Paramagnetic property over the ferrimagnetic property.•Possible use in microwave devices for the filter, sensing and switching purpose.