ULTRA-HIGH DENSITY MAGNETO-OPTICAL RECORDING SYSTEM

模拟了富过渡金属(TM)和富稀土(RE)的TbFeCo薄膜的热磁记录过程，假设束斑尺寸为1和0.1微米，其中壁能与温度的关系非常简单。对于富Tm的Tbl8(Fe78Co22)82薄膜，由于较大的杂散场，可以写入小于0.1微米的磁区。另一方面，对于富稀土的Tb25.6(Fe78Co22)74.4薄膜，由于壁能及其空间梯度所产生的较大的有效电场，无法写出小的磁畴。用扩展X射线吸收精细结构(EXAFS)谱估计了Dy/Fe多层膜的局部结构各向异性。傅立叶变换的Fe-EXAFS表明，面内和面外的原子配位不同。结构各向异性和垂直磁各向异性均随双层周期和制备方法的不同而变化。发现结构各向异性的变化与垂直磁各向异性的变化密切相关

Thermomagnetic recording process has been simulated for transition metal (TM) -rich and rare earth (RE) -rich TbFeCo films assuming beam spot size of 1 and 0.1 micron, where very simple temperature dependence is assumed for the wall energy. For the TM-rich Tbl8 (Fe78Co22) 82 film, domains smaller than 0.1 micron can be written owing to the large stray field. On the other hand, for the RE-rich Tb25.6 (Fe78Co22) 74.4 film, small domains cannot be written due to the large effective field which, originating from the wall energy and its spatial gradient, forces to shrink the domain.Local structural anisotropy was estimated using extended X-ray absorption fine structure (EXAFS) spectroscopy for Dy/Fe multilayers prepared by sputtering and vacuum deposition methods.Fourier transformed Fe-EXAFS indicated a difference in the atomic coordination between in-plane and out-of-plane. Both the structural anisotropy and the perpendicular magnetic anisotropy change depending on the bilayer period and the preparation methods. The variation of the structural anisotropy was found corresponds closely to that of the perpendicular magnetic anisotropy