High-Throughput Electronic Structure Analysis Using Composition-Spread Films
— A One-Day Experiment at NanoTerasu identifying the Optimal Half-Metal Composition Accelerates the Development of Spintronic Materials —2025.01.09
NIMS (National Institute for Materials Science)
Tohoku University
Photon Science Innovation Center (PhoSIC)
Japan Science and Technology Agency (JST)
A research team comprising members from NIMS, Tohoku University and PhoSIC has successfully identified the optimal composition of a Co-Mn-Si Heusler alloy exhibiting the highest spin polarization —a key property of half-metallic materials— in just one day of experiments.
Abstract
- A research team comprising members from the National Institute for Materials Science (NIMS), Tohoku University, and the Photon Science Innovation Center (PhoSIC) has successfully identified the optimal composition of a Co-Mn-Si Heusler alloy exhibiting the highest spin polarization—a key property of half-metallic materials—in just one day of experiments. This achievement was made possible by fabricating a composition-spread thin film on a single substrate and conducting photoelectron measurements at a 3 GeV high-brilliance synchrotron radiation facility, NanoTerasu. This highly efficient optimization approach is expected to accelerate the development of high-performance spintronic materials.
- Half-metallic materials are magnetic materials characterized by a high spin polarization, in which the spins of conduction electrons are aligned in a single direction. These materials are attracting attention as promising electrode candidates for next-generation hard disk drive read heads and other spintronic devices. However, direct measurement of spin polarization typically requires spin-resolved photoemission spectroscopy using low-energy photons in the VUV and soft X-ray regions, which is time-consuming. Therefore, faster methods for evaluating spin polarization are in increasing demand to enable more efficient materials development.
- To address this challenge, the research team set out to develop a new and efficient method for optimizing the composition of half-metallic materials. They focused on Co₂MnSi, a well-known representative half-metal, and fabricated a thin film on a single substrate with a gradient in the atomic composition ratio of cobalt (Co) and manganese (Mn), ranging from 10 to 40 at.%. Hard X-ray photoelectron spectroscopy (HAXPES) measurements using synchrotron radiation were carried out at a hard X-ray beamline BL09U of NanoTerasu. As a result, a large dataset on the composition-dependent electronic structure was obtained in just one day, and detailed analysis identified that the highest spin polarization is achieved around the composition with 27 at.% Mn.
- Looking ahead, this method is expected to accelerate the discovery and development of novel half-metallic materials, thereby contributing to the realization of high-performance spintronic devices.
- This research was conducted by a team comprising Dr. Ryo Toyama (NIMS Postdoctoral Researcher) and Dr. Yuya Sakuraba (Group Leader) from the Magnetic Functional Device Group, NIMS; Dr. Koichiro Yaji (Group Leader) and Dr. Shunsuke Tsuda (Senior Researcher) from the Photoemission Spectroscopy Group, NIMS; and Dr. Yuma Iwasaki (Senior Researcher) from the Data-Driven Materials Design Group, NIMS. The team also included Associate Professor Susumu Yamamoto from the International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University, and Dr. Hiroyuki Yamane (Chief Scientist) from the Photon Science Innovation Center (PhoSIC). The study was carried out as part of the JST CREST program “Exploring Innovative Materials in Unknown Search Space” (Grant Number: JPMJCR21O1).
- The results of this research were selected as an Editor’s Choice in Science and Technology of Advanced Materials and published online on January 7, 2025.
Figure. 3 GeV High-Brilliance Synchrotron Radiation Facility: NanoTerasu
Figure. Thin-Film Deposition System and Hard X-ray Photoelectron Spectroscopy Instruments
Published Paper
(”High-throughput evaluation of half-metallicity of Co2MnSi Heusler alloys using composition-spread films and spin-integrated hard X-ray photoelectron spectroscopy" Ryo Toyama, Shunsuke Tsuda, Yuma Iwasaki, Thang Dinh Phan, Susumu Yamamoto, Hiroyuki Yamane, Koichiro Yaji, Yuya Sakuraba; Journal: Science and Technology of Advanced Materials [January 7, 2025]; DOI : 10.1080/14686996.2024.2439781)
Contact information
（Regarding the research）
Yuya Sakuraba
Group Leader
Magnetic Functional Device Group
Research Center for Magnetic and Spintronics Materials
National Institute for Materials Science
Group Leader
Magnetic Functional Device Group
Research Center for Magnetic and Spintronics Materials
National Institute for Materials Science
Tel: +81-29-860-2708
E-Mail: SAKURABA.Yuya=nims.go.jp (Please change "=" to "@")
URL: https://www.nims.go.jp/mmu/mmg/ (Magnetic Functional Device Group's Website)
E-Mail: SAKURABA.Yuya=nims.go.jp (Please change "=" to "@")
URL: https://www.nims.go.jp/mmu/mmg/ (Magnetic Functional Device Group's Website)
Susumu Yamamoto
Associate Professor
International Center for Synchrotron Radiation Innovation Smart, Tohoku University
Concurrent : Institute of Multidisciplinary Research for Advanced Materials
Associate Professor
International Center for Synchrotron Radiation Innovation Smart, Tohoku University
Concurrent : Institute of Multidisciplinary Research for Advanced Materials
Tel: +81-22-752-2343
E-Mail: susumu=tohoku.ac.jp (Please change "=" to "@")
E-Mail: susumu=tohoku.ac.jp (Please change "=" to "@")
Hiroyuki Yamane
Chief Scientist
Photon Science Innovation Center
Chief Scientist
Photon Science Innovation Center
Tel: +81-22-785-9618
E-Mail: yamane=phosic.or.jp (Please change "=" to "@")
E-Mail: yamane=phosic.or.jp (Please change "=" to "@")
（For general inquiries）
Public Relations Office
National Institute for Materials Science
National Institute for Materials Science
Tel: +81-29-859-2026
Fax: +81-29-859-2017
E-Mail: pressrelease=ml.nims.go.jp (Please change "=" to "@")
Fax: +81-29-859-2017
E-Mail: pressrelease=ml.nims.go.jp (Please change "=" to "@")
General affairs section
International Center for Synchrotron Radiation Innovation Smart, Tohoku University
Address: 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8572, Japan
International Center for Synchrotron Radiation Innovation Smart, Tohoku University
Address: 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8572, Japan
Tel: +81-22-752-2331
E-Mail: sris-soumu=grp.tohoku.ac.jp (Please change "=" to "@")
E-Mail: sris-soumu=grp.tohoku.ac.jp (Please change "=" to "@")
Osamu Yamamoto
Aobayama Universe 306
Photon Science Innovation Center
Address: 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8572, Japan
Aobayama Universe 306
Photon Science Innovation Center
Address: 468-1 Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8572, Japan
Tel: +81-22-752-2210
E-Mail: info=phosic.or.jp (Please change "=" to "@")
E-Mail: info=phosic.or.jp (Please change "=" to "@")
（Regarding JST-CREST）
Yusuke Ando
Department of Strategic Basic Research
Japan Science and Technology Agency
Department of Strategic Basic Research
Japan Science and Technology Agency
Tel: +81-3-3512-3531
Fax: +81-3-3512-2066
E-Mail: crest=jst.go.jp (Please change "=" to "@")
Fax: +81-3-3512-2066
E-Mail: crest=jst.go.jp (Please change "=" to "@")
