Magnetic and self-biased properties of highly oriented M-type barium ferrite films on Pt-coated Si substrate by magnetron sputtering

Highly oriented M-type barium ferrite (BaM) thin films were deposited by sputtering on Pt-coated Si Substrate with different substrate temperatures. X-ray diffraction and atomic force microscopy results show that BaM films have crystal texture of c-axis grains perpendicular to film plane with apparent hexagonal morphology. On the other hand, it is clearly observed that the remanent magnetization (Mr) in out-plane is higher than those in in-plane, and the Mr in out-plane increases with increasing the substrate temperature, reaching maximum when substrate temperature (Ts) is 600 degrees C. The hysteresis curves also indicate that the BaM thin film exhibits nice self-biased property with 4 pi Mr of 3803.04 Gs, squareness ratio (Mr/Ms) of 0.96, and coercivity of 1767.3 Oe. These results make sure that these BaM films have potential for use in self-biasing microwave/millimeter wave magnetic devices such as circulators and isolators. (C) 2013 American Institute of Physics.