Effect of MgO underlayer misorientation on the texture and magnetic property of FePt–C granular film
Effect of MgO underlayer misorientation on the texture and magnetic property of FePt–C granular film
复制标题
DOI：
10.1016/j.actamat.2015.03.007
复制
发表时间：
2015-06
期刊：
影响因子：
9.4
通讯作者：
Jian Wang;S. Hata;Y. Takahashi;H. Sepehri-Amin;B. Varaprasad;T. Shiroyama;T. Schrefl;K. Hono
中科院分区：
文献类型：
--
作者：
Jian Wang;S. Hata;Y. Takahashi;H. Sepehri-Amin;B. Varaprasad;T. Shiroyama;T. Schrefl;K. Hono
利用透射电子显微镜（TEM）的取向映射技术和微磁学模拟研究了在MgO（0 0 1）衬底和（0 0 1）织构MgO衬底上沉积的FePtC颗粒膜的易磁化轴分布（EAD）对磁性的影响。与在单晶MgO（0 0 1）衬底上沉积的FePt-C薄膜相比，在多晶MgO衬底上沉积的FePt-C薄膜具有更小的垂直磁化率、更宽的开关场分布和可见的面内小回线。虽然晶粒尺寸和它们的分布在这两种膜看起来相似的TEM，取向映射和织构分析表明，多晶MgO底层引入显着的（0 0 1）织构FePt晶粒的取向差。通过引入从织构分析获得的FePt晶粒的特定取向差分布，微磁学模拟成功地再现了面内磁化中的大磁滞。研究表明，MgO底层的（0 0 1）织构的改善对降低FePt基记录介质的面内组分是至关重要的。
A transmission electron microscope (TEM) based orientation mapping technique and micromagnetic simulations were applied to study the influence of easy axis distribution (EAD) on magnetic properties of FePt–C granular films which were deposited on a single crystalline MgO (0 0 1) substrate and a (0 0 1)-textured poly-crystalline MgO underlayer. The FePt–C film on the polycrystalline MgO underlayer shows smaller perpendicular coercivity, broader switching field distribution and visible in-plane minor loop compared with that deposited on the single crystalline MgO (0 0 1) substrate. Although the grain sizes and their distributions in both films look similar in TEM, orientation mapping and texture analysis revealed that the polycrystalline MgO underlayer introduces significant misorientation in the (0 0 1)-textured FePt grains. Micromagnetic simulations successfully reproduced the large hysteresis in the in-plane magnetization by introducing the specific misorientation distribution of the FePt grains obtained from the texture analysis. The misoriented FePt grains were found to be grown from misoriented MgO grains, indicating that the improvement of the (0 0 1) texture of the MgO underlayer is essential to reduce the in-plane component of FePt based recording media.