Epitaxial growth of Zn2Y ferrite films by pulsed laser deposition

Oriented and single phase Ba2Zn2Fe12O22 (Zn2Y) thin films (similar to 5000 Angstrom thick) have been grown using pulsed laser deposition (ArF, 193 nm) on single-crystal (0001) sapphire substrates. A single phase polycrystalline Zn2Y target was used to deposit films. The composition, structure, and morphology of the films; were determined using Rutherford backscattering spectrometry, x-ray diffraction (XRD), and scanning electron microscopy. As a function of substrate temperature (>700 degrees C), films deposited in 200 mTorr of oxygen pressure were found to be deficient in Zn. The Zn deficiency increased with increasing substrate deposition temperature (<900 degrees C). Analysis of the XRD patterns indicated that films deposited from stoichiometric targets were primarily BaFe12O19 (BaM). Compensation of the target with excess Zn changed the structure of the film from BaM to a mixture of phases, i.e., BaM and Zn2Y. Highly oriented and single phase Zn2Y films could be achieved by depositing Zn2Y film onto ZnO (similar to 400 Angstrom) buffered sapphire substrates; Deposited films exhibit an epitaxial relationship of (001)Zn2Y//(001)ZnO//(001)Al2O3. The ferromagnetic resonance derivative linewidth of the Zn2Y film for an in-plane applied field was similar to 310 Oe, which is larger than expected for bulk single crystals. (C) 1999 American Vacuum Society. [S0734-2101(99)10405-6].