Max Planck Institute for Chemical Physics of Solids , Dresden 01187 , Germany.
Department of Physics , National Chung Cheng University , Chiayi 62102 , Taiwan.
ACS Appl Mater Interfaces. 2019 Sep 25;11(38):35162-35168. doi: 10.1021/acsami.9b12219. Epub 2019 Sep 11.
Materials with high spin-polarization play an important role in the development of spintronics. Co-based Heusler compounds are a promising candidate for practical applications because of their high Curie temperature and tunable half-metallicity. However, it is a challenge to integrate Heusler compounds into thin film heterostructures because of the lack of control on crystallinity and chemical disorder, critical factors of novel behaviors. Here, muscovite is introduced as a growth substrate to fabricate epitaxial CoMnGa films with mechanical flexibility. The feature of heteroepitaxy is evidenced by the results of X-ray diffraction and transmission electron microscopy. Moreover, high chemical ordering with superior properties is delivered according to the observation of large Hall conductivity (680 Ω cm) and highly saturated magnetic moment (∼3.93 μ/f.u.), matching well with bulk crystals. Furthermore, the excellence of magnetic and electrical properties is retained under the various mechanical bending conditions. Such a result suggests that the development of CoMnGa/muscovite heteroepitaxy provides not only a pathway to the thin film heterostructure based on high-quality Heusler compounds but also a new aspect of spintronic applications on flexible substrates.
具有高自旋极化率的材料在自旋电子学的发展中起着重要作用。基于 Co 的 Heusler 化合物由于其居里温度高和可调谐的半金属性，是实际应用的有前途的候选材料。然而，由于缺乏对结晶度和化学无序的控制，这是将 Heusler 化合物集成到薄膜异质结构中的一个挑战，而结晶度和化学无序是新行为的关键因素。在这里，云母被引入作为生长衬底来制造具有机械柔韧性的外延 CoMnGa 薄膜。X 射线衍射和透射电子显微镜的结果证明了异质外延的特征。此外，根据大霍尔电导率（680 Ω cm）和高饱和磁矩（~3.93 μ/f.u.）的观察，提供了具有优异性能的高化学有序性，与体晶体很好地匹配。此外，在各种机械弯曲条件下，磁性和电学性能的优异性能得以保持。这样的结果表明，CoMnGa/云母异质外延的发展不仅为基于高质量 Heusler 化合物的薄膜异质结构提供了途径，而且为柔性衬底上的自旋电子学应用提供了新的方面。
