High coercivity Co-ferrite thin films on SiO2 (100) substrate prepared by sputtering and PLD

Co-ferrite thin films with high coercivity were deposited on SiO₂ single crystal substrates by sputtering and pulsed laser deposition (PLD). All the films were subsequently annealed at a temperature from 500°C to 1200°C. Magnetic properties were found to be strongly related to annealing temperature, substrate, thickness and thin film deposition methods. A coercivity as high as 9.3 kOe was achieved in the 50 nm film after annealing at 900°C for 15 min deposited on (100)-SiO₂ substrate using sputtering. The high coercivity was associated with the nano-structure, relatively large micro-strain, and a high density of defects.