Role of dysprosium incorporation on structural and magnetic properties of yttrium iron garnet for high power microwave device applications

This study investigated the impact of dysprosium (Dy) substitution on the structural and magnetic characteristics of yttrium iron garnet (YIG) nanostructures. Dy substituted YIG (Y3-xDyxFe5O12; where x varied from 0 to 1.6 in steps of 0.2) samples were prepared using sol-gel auto combustion synthesis followed by calcination at 900 degrees C and heat treatment at 1300 degrees C for 8 h. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) techniques were used to analyze the structural and morphological properties. Energy-dispersive X-ray analysis (EDAX) was used to determine the samples' elemental composition. Differential scanning calorimetry (DSC) analyzed the magnetic phase transition. Field and temperature-dependent magnetization behavior was studied. The room temperature dielectric and permeability properties were measured in the frequency range of 1 MHz-1.8 GHz. The results revealed a cubic garnet phase with no other phases detected. The magnetic properties exhibited a decreasing trend of magnetization with increasing Dy concentration. The Curie temperature ranged from 545K to 570K. Thermal stability of magnetization increased with Dy concentration up to x = 1.2, then decreased with further increase. The electrical, magnetic, and dielectric properties changed with Dy substitution. The low magneto-dielectric losses, high resistivity, and high thermal stability make these samples suitable for high-power operated microwave devices.