Preferential Orientation and Magnetic Properties of Sputter-Deposited Fe3O4 Films

The authors studied the effects of the type of substrate rotation speed on Fe3O4 films formed by reactive sputtering, varying the layer deposition period D in the range from 2 to 30 Ã… while holding the film deposition rate R and substrate temperature T constant. Smaller periods D resulted in larger crystal grains. Films formed on glass, alumite, and (111) silicon substrates with small D were highly oriented in the ≪111≫ direction, while alignment in the ≪100≫ direction was enhanced in films deposited on (100) NaCl. Also, highly oriented films tended to exhibit high squareness ratios and low coercivities.