Element-Specific Evaluation of Magnetic Moments in Ferrimagnetic Mn2VAl Heusler Epitaxial Thin Films

Abstract

フェリ磁性ホイスラー合金Mn2VAlエピタキシャル薄膜の元素選択的磁気特性評価 Element-Specific Evaluation of Magnetic Moments in Ferrimagnetic Mn2VAl Heusler Epitaxial Thin Films T. Kubota1), K. Kodama2), T. Nakamura2), Y. Sakuraba3), M. Oogane1), H. Naganuma1), K. Takanashi3) and Y. Ando1) 1) Department of Applied Physics, Tohoku University 2) Japan Synchrotron Radiation Research Institute (JASRI) / SPring-8 3) Institute for Materials Research, Tohoku University Abstract We successfully fabricated L21-ordered Mn2VAl Heusler thin films and evaluated their ferrimagnetic properties by soft x-ray magnetic circular dichroism (XMCD). The buffer layers and annealing temperatures were varied to prepare the Mn2VAl films. We discovered that Mn2VAl could be ordered in an L21 phase well when it was deposited directly onto an MgO (001) single crystalline substrate. The maximum values of L21 and B2 long-range order parameters we obtained were about 0.5 for both phases for samples without a buffer layer, when substrates were heated at 500°C or 600°C. The saturation magnetization (Ms) for these samples was roughly 150 emu/cc. This is rather small compared to that expected from the ideal Slater-Pauling behavior, which might be due to the suppressed degree of L21 or B2 ordering. Ferrimagnetism in the Mn2VAl, ferrimagnetic coupling between Mn and V moments was clearly observed by using the XMCD technique in well-ordered L21-Mn2VAl film as has been predicted in theoretical investigations. Key words Heusler alloy, Mn2 VAl, x-ray absorption spectroscopy, magnetic circular dichroism, ferrimagnet, thin film Authors: 窪田, 崇秀 児玉, 謙司 中村, 哲也 桜庭, 裕弥 大兼, 幹彦 永沼, 博 高梨, 弘毅 安藤, 康夫 フェリ磁性ホイスラー合金Mn2VAlエピタキシャル薄膜の元素選択的磁気特性評価 窪田 崇秀1), 児玉 謙司2), 中村 哲也2), 桜庭 裕弥3), 大兼 幹彦1), 永沼 博1), 高梨 弘毅3), 安藤 康夫1) 1) 東北大学大学院工学研究科応用物理学専攻 2) 高輝度光化学研究センター/ SPring-8 3) 東北大学金属材料研究所 Abstract We successfully fabricated L21-ordered Mn2VAl Heusler thin films and evaluated their ferrimagnetic properties by soft x-ray magnetic circular dichroism (XMCD). The buffer layers and annealing temperatures were varied to prepare the Mn2VAl films. We discovered that Mn2VAl could be ordered in an L21 phase well when it was deposited directly onto an MgO (001) single crystalline substrate. The maximum values of L21 and B2 long-range order parameters we obtained were about 0.5 for both phases for samples without a buffer layer, when substrates were heated at 500°C or 600°C. The saturation magnetization (Ms) for these samples was roughly 150 emu/cc. This is rather small compared to that expected from the ideal Slater-Pauling behavior, which might be due to the suppressed degree of L21 or B2 ordering. Ferrimagnetism in the Mn2VAl, ferrimagnetic coupling between Mn and V moments was clearly observed by using the XMCD technique in well-ordered L21-Mn2VAl film as has been predicted in theoretical investigations. Key words Heusler alloy, Mn2 VAl, x-ray absorption spectroscopy, magnetic circular dichroism, ferrimagnet, thin film