Alternating target laser ablation deposition of high quality barium hexaferrite thin films from barium monoferrite and hematite targets

摘要

An optimized alternating target laser ablation deposition (ATLAD) technique has been developed to grow high quality barium hexaferrite (BaFe_(12)O_(19)) thin films on basal plane oriented sapphire (Al_2O_3) substrates from barium monoferrite (BaFe_2O_4) and hematite (alpha-Fe_2O_3) targets. Crystallographic and structural characterization results show that the films possess low c-axis dispersion of DELTA omega=0.259 deg and hexagonal terraced surface morphology. Saturation magnetization and uniaxial magnetic anisotropy field were determined to be consistent with reference data on high quality barium hexaferrite films and bulk single crystals grown by other techniques. Ferromagnetic resonance linewidth of 42 Oe was measured at 52 GHz by the shorted waveguide technique. We conclude that the ATLAD technique is capable of growing high quality barium hexaferrite films while providing unique opportunities to control the ionic distribution in the hexagonal unit cell by allowing different species of ions to be introduced from the respective targets in any order and at any time during film growth.