Effect of lamination period and deposition angle on FeAlN-Al2O3 multilayers

Magnetic properties and microstructure have been investigated as a function of lamination period in 1-mu m-thick FeAlN/Al2O3 multilayers. It has been seen that coercivity is weakly dependent on FeAlN thickness in the laminati on, consistent with a change in morphology. Within this thickness range, H- k is reduced and dispersion increases accordingly. As the deposition angle is increased from 0 degrees to 40 degrees, there is little change in coerci vity, while H-k increases, from 4 to 8 Oe. Saturation magnetostriction was found to exhibit a strong linear dependence (from +1x10(-6) to -5x10(-6)) o ver the thickness range studied, with weak dependence on the deposition ang le. High frequency permeability degraded with increasing FeAlN thickness, w hich is believed to reflect the reduced anisotropy in these samples. Micros tructural analysis via x-ray diffraction and transmission electron microsco py has indicated that the films contain predominately alpha-Fe, and that Al 2O3 spacer layers of 20 Angstrom are sufficient to interrupt columnar grain growth. Furthermore, columnar grains formed in samples with thick FeAlN la yers do not exhibit canting when grown on tilted substrates. (C) 2000 Ameri can Institute of Physics. [S0021-8979(00)40308-7].