Magnetic Microstructure of L1{sub}0 (Fe{sub}0.55Pt{sub}0.45){sub}78Zr{sub}(2-4)B{sub}(18-20) Nanocrystalline Alloys Observed by Electron Holography

摘要

The ordered L1{sub}0 phase of FePt alloy is characterized by a high uniaxial magnetocrystalline anisotropy of 7*10{sup}6J/m{sup}3 along the easy c-axis [1]. It has long been anticipated as materials for permanent magnets and magnetic recording media. The ordered L1{sub}0 Fe-Pt phase was directly formed by rapidly quenching the melt with the simultaneous addition of B and Zr. The melt-spun (Fe{sub}0.55Pt{sub}0.45){sub}78Zr{sub}2B{sub}20 and (Fe{sub}0.55Pt{sub}0.45){sub}78Zr{sub}4B{sub}18 alloys exhibit high coercivity of 341kA/m and 649kA/m, respectively [2]. On the other hand, electron holography is an important technology to analyze the magnetic microstructure of a variety of magnetic materials [3]. In this report, the magnetic microstructures of the melt-spun(Fe{sub}0.55Pt{sub}0.45){sub}78Zr{sub}2B{sub}20 and (Fe{sub}0.55Pt{sub}0.45){sub}78Zr{sub}4B{sub}18 in as-quenched state were investigated by Lorentz microscopy and electron holography.