L1$_{0}$-Ordered FePt-Based Perpendicular Magnetic Recording Media for Heat-Assisted Magnetic Recording

Abstract

We update our continuous effort to optimize the microstructures and magnetic properties of FePt-X granular films to achieve an ideal media structure on glass substrates for heat-assisted magnetic recording. For segregant X, we investigated C, SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and their mixtures. While FePt-C granular films show excellent inplane granular structure for the thickness (t) smaller than 6 nm, a second layer appears for t >; 6 nm. On the other hand, FePt-TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> granular film shows a columnar structure with a smooth surface, but the inplane morphology is interconnected. To enhance the phase separation and realize the laterally isolated columnar structure, we mixed the segregant materials of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> or TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with C. We also used the thin FePt-C films as templates for FePt-X(X=SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) since the FePt-C showed good particle separation with the fine particle size. Based on these experimental results, we discuss how to attain the ideal media structure for heat-assisted magnetic recording.