Effect of Annealing Temperature on the Structural and Magnetic Properties of Terbium Iron Garnet Thin Films Prepared by Sol-Gel Method

Abstract

The terbium iron garnet (TbIG) nanoparticle thin films have been prepared by a sol-gel method for potential use as a magnetic sensor. The films were deposited onto clean quartz substrate using a spin coating technique, followed by annealing at different temperature of 700, 800, 900 °C in air for 2 h. As prepare film has been also executed. Microstructural and magnetic properties of the films were measured using an X-ray diffraction (XRD), a Field Emission Scanning Electron Microscope and a Vibrating Sample Magnetometer. The XRD results revealed that the pure phase of garnet structure has been formed at 900 °C. The lattice parameter decreased initially from 11.6 to 11.4 A when annealing temperature increased from 700 to 800 °C, and then it is increased to 12.36 A when annealing temperature increased to 900 °C. The grain sizes increased from 12 to 18 nm with increasing of annealing temperature from 700 to 900 °C, while the thickness of the films decreased to the smallest value of 312 nm at 900 °C. The saturation magnetization increased with increasing of annealing temperature due to increasing of grain sizes. The coercivity of films exhibited a highest value of 102 kA/m at 900 °C.