Magnetic and microstructural characterization of FeTaN high saturation materials for recording heads

Magnetically soft FeTaN high saturation materials have been deposited on both sloping and planar surfaces by RF reactive sputtering with an appropriate high substrate bias. A perpendicular anisotropy component accompanying degrading soft magnetic properties is observed under low substrate bias. This undesirable perpendicular anisotropy in the FeTaN films arises from the magnetoelastic anisotropy due to in-plane compressive stress and positive magnetostriction constant and from the magnetocrystalline anisotropy due to out-of-plane [200] easy axes. This is supported by X-ray pole figures, temperature-dependent VSM measurements, and synchrotron radiation X-ray stress measurements. The absence of microshape perpendicular anisotropy is supported by SQUID measurements and high resolution TEM images. This work has identified the processing parameters and microstructures that are critical for successfully incorporating high saturation magnetic materials in recording heads.