Structure and Magnetic Properties of FeCo Epitaxial Thin Films
Structure and Magnetic Properties of FeCo Epitaxial Thin Films
复制标题
FeCo外延薄膜的结构和磁性能
DOI：
10.3379/msjmag.0901rb8031
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发表时间：
2009
影响因子：
--
通讯作者：
M. Futamoto
中科院分区：
文献类型：
--
作者：
Kouhei Shikada;M. Ohtake;F. Kirino;M. Futamoto
采用超高真空分子束外延技术在MgO（100）、MgO（110）和MgO（111）单晶衬底上制备了FeCo薄膜。研究了衬底取向和衬底温度对薄膜生长结构和磁性能的影响。具有平行于衬底表面的（100）bcc、（211）bcc和（110）bcc平面的FeCo薄膜在相应的MgO衬底上外延生长。在MgO（100）衬底上制备了FeCo（100）bcc单晶薄膜。在MgO（110）衬底上外延生长的FeCo（211）bcc双晶薄膜具有两种畴，畴的取向绕薄膜法线旋转180度。FeCo（110）bcc薄膜在MgO（111）衬底上的外延生长具有两种类型的变体，即Nishiyama-Wasserman和Kurdjumov-Sachs关系。原子尖锐的边界之间的FeCo薄膜和MgO衬底，其中失配位错引入的FeCo薄膜，大概是为了减少晶格失配。对于在100 °C的衬底温度下制备的FeCo薄膜，观察到垂直于衬底表面的晶格间距减小0.3%。随着衬底温度的升高，晶格间距减小。在MgO衬底上生长的FeCo薄膜的磁性能受到磁晶各向异性和由形成FeCo薄膜的FeCo岛的粗糙度引起的形状各向异性的影响。
FeCo thin films were prepared on MgO(100), MgO(110), and MgO(111) single-crystal substrates by UHV-MBE. The effects of substrate orientation and substrate temperature on the film growth structure and the magnetic properties were investigated. FeCo thin films with (100)bcc, (211)bcc, and (110)bcc planes parallel to the substrate surface grew epitaxially on respective MgO substrates. FeCo(100)bcc single-crystal films were obtained on MgO(100) substrates. FeCo(211)bcc bi-crystalline films grew epitaxially on MgO(110) substrates with two types of domains whose orientations were rotated around the film normal by 180 degrees with respect to each other. FeCo(110)bcc thin films grew epitaxially on MgO(111) substrates with two type variants namely, the Nishiyama-Wasserman and Kurdjumov-Sachs relationships. Atomically sharp boundaries were recognized between the FeCo thin films and the MgO substrates, where misfit dislocations were introduced in the FeCo thin films, presumably to decrease the lattice misfits. A 0.3% reduction of the lattice spacing normal to the substrate surface was observed for an FeCo thin film prepared at a substrate temperature of 100 °C. The lattice spacing reduction decreased with increasing substrate temperature. The magnetic properties of FeCo thin films grown on MgO substrates were influenced by the magnetocrystalline anisotropy and the shape anisotropy caused by the roughness of FeCo islands which form the FeCo thin films.