Structural elucidation and magnetic behaviour evaluation of gallium substituted garnet ferrites

Abstract Impact of gallium (Ga) on structural, morphological and magnetic properties of yttrium iron garnet (YIG) nano-sized ferrites with nominal composition (Y3GaxFe5-xO12, where x = 0.00, 0.40, 0.80, 1.20, 1.60) has been investigated. The samples were prepared via sol-gel auto combustion route. XRD (X-ray diffraction), FESEM (field emission scanning electron microscopy) and VSM (vibrating sample magnetometer) were used to unfold the structural, morphological and magnetic properties of Ga substituted YIG ferrites. Single phase structure of all samples was confirmed through XRD. Cations distribution such as site radii, hopping bond length, shared and unshared edges of the Ga substituted YIG ferrites were also determined. Physical properties such as X-ray density (Dxrd), bulk density (Dbulk), porosity and lattice parameters were found to increase with increasing Ga concentration. FESEM images represented well crystallized and homogenous grains for YIG whereas porous structures were found for Ga substituted ferrites. The grain size of these samples was found in the nano regime (40–86 nm). Magnetic properties such as magnetic saturation, coercivity, remanence, initial permeability, Bohr magneton and anisotropy constant (K) were calculated from hysteresis loops. However, Yafet and Kittle (Y-K) angles were also calculated. Y-K angles were increased with Ga concentration in YIG nano-sized ferrites. Low coercivity and moderate magnetization suggested the use of these ferrites for electromagnetic microwave absorption and frequency agile antenna for wireless communication. Furthermore, the range of operated frequency in microwave region of these nanoferrites suggests the use of these ferrites for high frequency (S and C bands) applications.