Magnetic, DC Electrical, and Impedance Properties of Zn Doped Yttrium Iron Garnet Nanoparticles

Y3Fe5-xZnxO12 with x = 0; 0.02; 0.04; 0.06; 0.08; 0.1 (YIG) particle materials were fabricated by sol-gel method combined with heat treatment at 900 °C and 1,000 °C with different annealing times (2 h and 5 h) and heating rates (5 °C/min and 2 °C/min).  X-ray diffraction patterns show that the obtained samples are single crystalline phases at the condition of an annealing temperature of 900 °C for 5 h and a heating rate of 2 degrees/min. FESEM images of the samples show particle sizes from the submicron to the micrometer. The magnetization of the samples decreases as the doping concentration increases. I-V characteristics and complex impedance spectra at room temperature of samples were measured. The results show that the resistivity value of the doped samples decreases in the range of 5-6 orders in magnitude compared with that of the pure YIG sample. The contribution of the grain boundaries to the impedance was analyzed. The conducting process is explained due to the tunneling of charge carriers across the grain boundary.