Structural and magnetic properties of yttrium iron garnet nanoparticles doped with copper obtained by sol gel method

Abstract In this work, we have studied the structural and magnetic properties of yttrium iron garnet nanoparticles doped with copper obtained by sol gel method. The lattice parameter decreases from 12.3779 A to 12.3774 A, for low doping and increases from 12.3788 A to 12.3814 A for high copper concentrations. The variation in the crystallite size was related with defects and internal stress produced by the dopant addition. The micrographs showed a similar format, rounded irregular form and lengthened, for all samples. Saturation magnetization (Ms) confirmed the substitution of Fe/Cu in the octahedral sites of YIG. Ms increased from 24.04 emu/g to 29.49 emu/g for dopant concentration varying from 0.00 to 0.01. For y = 0.03 the Ms = 26.05 emu/g and for y = 0.05, Ms = 26.35 emu/g. Changes in the coercivity (Hc) values are attributed to the pinning centers existence and particle format.