[22a-B201-1~11] 10.1 Emerging materials in spintronics and magnetics (including fabrication and characterization methodologies)

▼ [22a-B201-5] Epitaxial growth of tetragonal Mn-based ultrathin films on highly mismatched substrate

〇(M1C)Naoki Kamata^1,2, Shigemi Mizukami^2,3, Kazuya Suzuki^4,2 (1.Dept. Appl Phys, Touoku Univ., 2.WPI-AIMR, Tohoku Univ., 3.CSIS, Tohoku Univ., 4.ASRC, JAEA)

Keywords:spintronics and magnetics, thin film and surface

Tetragonal Mn-based alloy thin films are attractive materials as a perpendicularly magnetized electrode of functional magnetic tunnel junctions for memory devices, high frequency devices and sensors. However, their excellent properties have been only reported in single crystalline thin films grown on unpractical and expensive MgO single crystalline substrate. Therefore, the development of new epitaxial techniques using practical substrate will realize new applications of Mn-based alloys to the commercial applications. In this study, we focused on the single-crystal sapphire as a substrate, because this substrate has been broadly used in the epitaxial growth of compound semiconductors in mass production process. However, large lattice mismatch(~18%) and different crystal symmetry seem to be impossible to grow the high-quality epitaxial thin film of Mn-based alloy. In this study, we demonstrate the high-quality epitaxial growth of L1₀-MnGa ultrathin film on the sapphire(r-plane) substrate using bcc-Ta/Cr hybrid buffer layers.