Surface-specific thermal spin-depolarization on the half-metallic Heusler films

Abstract Half-metallic ferromagnets exhibit a perfect spin-polarization at the Fermi energy. Among many candidates, Co2MnSi Heusler alloy is the most investigated material due to its half-metallic nature and high Curie temperature (T C). Magnetic junction devices using Co2MnSi show remarkable perfor...

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Main Authors: Kazuki Sumida, Masaaki Kakoki, Yuya Sakuraba, Keisuke Masuda, Kazuki Goto, Takashi Kono, Koji Miyamoto, Yoshio Miura, Kazuhiro Hono, Taichi Okuda, Akio Kimura
Format: Article
Language:English
Published: Nature Portfolio 2025-01-01
Series:Communications Physics
Online Access:https://doi.org/10.1038/s42005-024-01918-w
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author Kazuki Sumida
Masaaki Kakoki
Yuya Sakuraba
Keisuke Masuda
Kazuki Goto
Takashi Kono
Koji Miyamoto
Yoshio Miura
Kazuhiro Hono
Taichi Okuda
Akio Kimura
author_facet Kazuki Sumida
Masaaki Kakoki
Yuya Sakuraba
Keisuke Masuda
Kazuki Goto
Takashi Kono
Koji Miyamoto
Yoshio Miura
Kazuhiro Hono
Taichi Okuda
Akio Kimura
author_sort Kazuki Sumida
collection DOAJ
description Abstract Half-metallic ferromagnets exhibit a perfect spin-polarization at the Fermi energy. Among many candidates, Co2MnSi Heusler alloy is the most investigated material due to its half-metallic nature and high Curie temperature (T C). Magnetic junction devices using Co2MnSi show remarkable performance at low temperatures. However, the performance is significantly degraded at room temperature, which requires a detailed understanding of the temperature-dependent electronic structure of Co2MnSi films. Here, using surface-sensitive spin- and angle-resolved photoelectron spectroscopy combined with first-principles calculations, we verify the temperature- and momentum-dependent spin-polarization of Co2MnSi thin-film. The recorded spin-polarization reaches  ~ 60-75% at 50 K, while it reduces  ~ 30-50% at 300 K. The observed surface-specific spin-depolarization behavior can be described by the thermally excited magnon model even well below T C, and we conclude that the spin-fluctuation is markedly enhanced on its surface. Our findings provide insights into the temperature-dependent electronic structure of half-metallic Heusler films, which could have significant implications for future spintronic applications.
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institution Kabale University
issn 2399-3650
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spelling doaj-art-5e126978b28a4285b72061e10c229c732025-01-05T12:32:46ZengNature PortfolioCommunications Physics2399-36502025-01-01811710.1038/s42005-024-01918-wSurface-specific thermal spin-depolarization on the half-metallic Heusler filmsKazuki Sumida0Masaaki Kakoki1Yuya Sakuraba2Keisuke Masuda3Kazuki Goto4Takashi Kono5Koji Miyamoto6Yoshio Miura7Kazuhiro Hono8Taichi Okuda9Akio Kimura10Research Institute for Synchrotron Radiation Science, Hiroshima UniversityGraduate School of Advanced Science and Engineering, Hiroshima UniversityResearch Center for Magnetic and Spintronic Materials, National Institute for Materials ScienceResearch Center for Magnetic and Spintronic Materials, National Institute for Materials ScienceResearch Center for Magnetic and Spintronic Materials, National Institute for Materials ScienceGraduate School of Science, Hiroshima UniversityResearch Institute for Synchrotron Radiation Science, Hiroshima UniversityResearch Center for Magnetic and Spintronic Materials, National Institute for Materials ScienceResearch Center for Magnetic and Spintronic Materials, National Institute for Materials ScienceResearch Institute for Synchrotron Radiation Science, Hiroshima UniversityGraduate School of Advanced Science and Engineering, Hiroshima UniversityAbstract Half-metallic ferromagnets exhibit a perfect spin-polarization at the Fermi energy. Among many candidates, Co2MnSi Heusler alloy is the most investigated material due to its half-metallic nature and high Curie temperature (T C). Magnetic junction devices using Co2MnSi show remarkable performance at low temperatures. However, the performance is significantly degraded at room temperature, which requires a detailed understanding of the temperature-dependent electronic structure of Co2MnSi films. Here, using surface-sensitive spin- and angle-resolved photoelectron spectroscopy combined with first-principles calculations, we verify the temperature- and momentum-dependent spin-polarization of Co2MnSi thin-film. The recorded spin-polarization reaches  ~ 60-75% at 50 K, while it reduces  ~ 30-50% at 300 K. The observed surface-specific spin-depolarization behavior can be described by the thermally excited magnon model even well below T C, and we conclude that the spin-fluctuation is markedly enhanced on its surface. Our findings provide insights into the temperature-dependent electronic structure of half-metallic Heusler films, which could have significant implications for future spintronic applications.https://doi.org/10.1038/s42005-024-01918-w
spellingShingle Kazuki Sumida
Masaaki Kakoki
Yuya Sakuraba
Keisuke Masuda
Kazuki Goto
Takashi Kono
Koji Miyamoto
Yoshio Miura
Kazuhiro Hono
Taichi Okuda
Akio Kimura
Surface-specific thermal spin-depolarization on the half-metallic Heusler films
Communications Physics
title Surface-specific thermal spin-depolarization on the half-metallic Heusler films
title_full Surface-specific thermal spin-depolarization on the half-metallic Heusler films
title_fullStr Surface-specific thermal spin-depolarization on the half-metallic Heusler films
title_full_unstemmed Surface-specific thermal spin-depolarization on the half-metallic Heusler films
title_short Surface-specific thermal spin-depolarization on the half-metallic Heusler films
title_sort surface specific thermal spin depolarization on the half metallic heusler films
url https://doi.org/10.1038/s42005-024-01918-w
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