Structure and Magnetic Properties of (001) Oriented CoPt-Ag and CoPd-Ag Alloy Films
Structure and Magnetic Properties of (001) Oriented CoPt-Ag and CoPd-Ag Alloy Films
复制标题
DOI：
10.3379/msjmag.1512r003
复制
发表时间：
2016
影响因子：
--
通讯作者：
T. Nagata;Y. Tokuoka;T. Kato;D. Oshima;S. Iwata
中科院分区：
文献类型：
--
作者：
T. Nagata;Y. Tokuoka;T. Kato;D. Oshima;S. Iwata
采用分子束外延技术在MgO（001）衬底上生长了20 nm厚的（CoPt）100-xAgx和（CoPd）100-xAgx（001）薄膜（x = 0-20），并与FePt-Ag和FePd-Ag薄膜的晶体结构和磁性进行了比较[Y. Tokuoka等人：应用物理学杂志，115，17 B716（2014）]，用于系统研究Ag添加到过渡金属-贵金属合金膜中的效果。对于CoPt-Ag，添加5%的Ag增加了垂直磁各向异性（PMA）和磁化率。然而，对于CoPd-Ag，Ag的添加既不提高PMA也不提高矫顽力。对CoPt-Ag和CoPd-Ag薄膜的结构分析表明，Ag的加入促进了CoPt-Ag薄膜的L10相有序化，而CoPd-Ag薄膜没有发现L10相有序化。虽然在CoPt-Ag和FePt-Ag之间添加Ag的效果有一些相似之处，例如增加PMA，矫顽力和L10有序，但在CoPd-Ag和FePd-Ag之间的PMA和L10有序有不同的趋势，除了两种膜都显示出随着Ag的添加而降低的矫顽力。Ag的偏析和L10有序化被认为是解释Ag的加入引起的结构和磁性变化的重要因素。
20-nm-thick (CoPt)100–xAgx and (CoPd)100–xAgx (001) films (x = 0–20) were grown on MgO(001) substrate at a temperature of 300uC by molecular beam epitaxy, and their crystal structure and magnetic properties were compared with those of FePt-Ag and FePd-Ag films [Y. Tokuoka et al.: J. Appl. Phys., 115, 17B716 (2014)] for the systematic study of the effect of Ag addition into transition metal – noble metal alloy films. For the CoPt-Ag, the addition of 5% Ag increased perpendicular magnetic anisotropy (PMA) and coercivity. However, for the CoPd-Ag, Ag addition enhanced neither the PMA nor the coercivity. Structural analysis of the CoPt-Ag and CoPd-Ag films revealed that Ag addition promoted L10 phase ordering for CoPt-Ag, while L10 ordering was not found in CoPd-Ag. Although there were some similarities in the effect of Ag addition between CoPt-Ag and FePt-Ag, such as increased PMA, coercivity, and L10 ordering, there were different trends in PMA and L10 ordering between CoPd-Ag and FePd-Ag, except that both films showed reduced coercivity with Ag addition. Ag segregation and L10 ordering are considered important factors to explain the variations of structure and magnetic properties with Ag addition.