{ "id": "eppscwyyqd", "slug": "masato-sagawa", "title": "Masato Sagawa", "updated": "2026-10-15", "topic_path": [ { "id": "physical", "label": "Physical world and mathematics", "api_url": "https://www.edgepedia.org/api/v1/topics/physical" }, { "id": "physical.scientists", "label": "Physical and mathematical scientists", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.scientists" }, { "id": "physical.scientists.physics-astronomy", "label": "Physicists and astronomers", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.scientists.physics-astronomy" }, { "id": "physical.scientists.physics-astronomy.phys-cmp", "label": "Researchers in condensed matter physics and quantum materials", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.scientists.physics-astronomy.phys-cmp" }, { "id": "physical.scientists.physics-astronomy.phys-cmp.magnetism-and-magnetic-materials", "label": "Magnetism and magnetic materials", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.scientists.physics-astronomy.phys-cmp.magnetism-and-magnetic-materials" } ], "geo": [ { "id": "geo.asia.t1946.physical.scientists.physics-astronomy", "label": "Asia (other) · 1946 to 2000: Physicists and astronomers", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t1946.physical.scientists.physics-astronomy", "path": [ { "id": "geo.asia", "label": "Asia (other)", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia" }, { "id": "geo.asia.t1946", "label": "Asia (other) · 1946 to 2000", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t1946" }, { "id": "geo.asia.t1946.physical", "label": "Physical world and mathematics", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t1946.physical" }, { "id": "geo.asia.t1946.physical.scientists", "label": "Physical and mathematical scientists", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t1946.physical.scientists" }, { "id": "geo.asia.t1946.physical.scientists.physics-astronomy", "label": "Physicists and astronomers", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t1946.physical.scientists.physics-astronomy" } ] } ], "excerpt": "Masato Sagawa (佐川眞人), born 1943 in Tokushima, Japan, is a Japanese materials scientist who invented the sintered Nd-Fe-B permanent magnet in 1982, now used in electric-vehicle motors and wind turbines.", "snippet": "Masato Sagawa (佐川眞人), born 1943 in Tokushima, Japan, is a Japanese materials scientist who invented the sintered Nd-Fe-B permanent magnet in 1982, now used in electric-vehicle motors and wind turbines.", "node": "physical.scientists.physics-astronomy.phys-cmp.magnetism-and-magnetic-materials", "markdown": "# Masato Sagawa\n\n**Masato Sagawa** (佐川眞人; born 1943 in Tokushima, Japan) is a Japanese inventor and materials scientist who created the sintered Nd-Fe-B (neodymium-iron-boron) permanent magnet in 1982, the strongest industrially manufactured magnet in the world.[1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942) • [2](https://link.springer.com/rwe/10.1007/978-981-19-9644-3_36-1) His magnet, with a maximum energy product almost double that of the samarium-cobalt magnets it displaced, now underpins electric-vehicle motors, wind-turbine generators, hard disk drives, phones, and appliances.[3](https://www.japanprize.jp/en/prize_past_2012_prize02.html) • [4](https://www.sciencedirect.com/science/article/pii/S1567271918300039)\n\n| Key fact | Detail |\n|---|---|\n| Born | 1943, Tokushima Prefecture, Japan[1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942) |\n| Signature invention | Sintered Nd-Fe-B magnet, 1982, at age 38; Curie temperature 310 °C, maximum energy product 35 MGOe[5](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/) • [6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) |\n| Career | Fujitsu 1972–1982; Sumitomo Special Metals 1982–1988; founder of Intermetallics (1988) and NDFEB Corporation (2013)[5](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/) • [7](https://qeprize.org/winners/dr-masato-sagawa) |\n| Patents | Over 60 global patents[1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942) |\n| Market today | Over 200,000 tonnes of Nd₂Fe₁₄B produced yearly, sales of about 30 billion dollars[8](https://www.kva.se/evenemang/invention-industrialization-and-basic-research-of-the-nd-fe-b-magnets/) |\n| Honors | Japan Prize 2012; Queen Elizabeth Prize for Engineering 2022 (sole recipient); European Inventor Award 2024; Honda Prize 2023 and IEEE 2022 Medal shared with John J. Croat[9](https://qeprize.org/winners/the-worlds-strongest-permanent-magnet) • [1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942) • [10](https://www.bbc.co.uk/news/science-environment-60205351) • [11](https://sj.jst.go.jp/news/202312/n1204-01p.html) |\n\n## Early life and education\n\nSagawa was born in 1943 in Tokushima Prefecture. He graduated from Kobe University's Faculty of Engineering in 1966, completed a master's in electrical engineering there in 1968, and received his doctorate from Tohoku University in 1972; Kobe University's account records the doctorate as being in metallurgical engineering.[5](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/) He joined Fujitsu's laboratories in 1972, working on magnetic materials for electric relays.[7](https://qeprize.org/winners/dr-masato-sagawa)\n\n**The 1978 clue.** In 1978 Sagawa heard a symposium lecture by Dr. Masaaki Hamano explaining that in crystal structures composed of rare earth and iron, the interatomic distance of the iron was too close, which causes a low [Curie temperature](https://www.edgepedia.org/curie-temperature); a related formulation he recalled was that iron cannot make a permanent magnet because the distance between its atoms is too short.[6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) • [5](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/) Sagawa reasoned that if elements with small atomic diameter, such as carbon or boron, were placed between the rare-earth and iron atoms, the iron-to-iron distance would be extended and the Curie temperature raised.[6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf)\n\n## The 1982–1984 discovery of Nd-Fe-B\n\nAt Fujitsu, Sagawa pursued the idea as private research for five years, patenting it in the early 1980s.[7](https://qeprize.org/winners/dr-masato-sagawa) His employer would not support full-scale development, so he moved to Sumitomo Special Metals (now Proterial, formerly Hitachi Metals, NEOMAX), which took notice of the magnet's potential.[6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) The world-record sintered magnet was born in 1982, about five years after his initial inspiration, when Sagawa was 38.[6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) • [5](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/)\n\nHe unveiled the breakthrough at the [Magnetism](https://www.edgepedia.org/magnetism) and Magnetic Materials Conference in [Pittsburgh](https://www.edgepedia.org/pittsburgh) in November 1983, and the full account of the sintered invention was published in 1984.[1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942) • [4](https://www.sciencedirect.com/science/article/pii/S1567271918300039) The basic technology for commercial production was established within a decade of the 1982 invention, and mass production began only three years after the 1982 patent application.[4](https://www.sciencedirect.com/science/article/pii/S1567271918300039) • [11](https://sj.jst.go.jp/news/202312/n1204-01p.html)\n\n## How the neodymium magnet works\n\nThe magnet is based on the ternary intermetallic compound Nd₂Fe₁₄B. Boron expands the iron-to-iron atomic distance in the iron-rich rare-earth phase, which raises the Curie temperature to 310 °C and allows the compound to retain useful magnetization at operating temperatures.[12](https://www.nature.com/articles/d42473-023-00333-z) • [6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) The compound also has a high anisotropy field of 6.7 T at room temperature, which is what allows a strong permanent field to be locked in.[13](https://docs.nlr.gov/docs/fy24osti/88583.pdf)\n\n**Sintering and coercivity.** Sagawa's route is powder metallurgy: powders are made, compacted by pressing, and baked in a vacuum.[12](https://www.nature.com/articles/d42473-023-00333-z) During sintering a cellular structure forms automatically around the aligned grains, and this structure contributes to the alloy's coercivity, its resistance to demagnetization.[14](https://spectrum.ieee.org/the-men-who-made-the-magnet-that-made-the-modern-world) In Sagawa's own explanation, adding slightly excess neodymium means the surplus neodymium surrounds the grains and forms the cell-like structure that produces coercivity.[15](http://www.daido.co.jp/neodymium_sagawa/interview/)\n\nThe raw compound alone was not an industrial material. Early Nd-Fe-B magnets suffered sudden reduction of magnetic coercivity under high temperatures, fragility, and performance loss through oxidation; Sagawa addressed these with additive elements, the sintered-magnet manufacturing technique, and a surface treatment that prevents oxidation.[3](https://www.japanprize.jp/en/prize_past_2012_prize02.html)\n\n## How it compares with other magnets\n\nBefore 1982 the best magnets were samarium-cobalt, refined in the 1970s, but both cobalt and samarium were scarce and costly resources that could not meet large demand.[6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) Sagawa's composition replaced them with abundant iron and neodymium plus a small amount of boron, and almost doubled the performance of the previous best.[9](https://qeprize.org/winners/the-worlds-strongest-permanent-magnet) The 1982 magnet reached a maximum energy product of 35 MGOe, nearly double that of traditional Sm-Co magnets, with a Curie temperature of 310 °C.[6](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf) • [3](https://www.japanprize.jp/en/prize_past_2012_prize02.html)\n\n**Sintered versus bonded.** [John J. Croat](https://www.edgepedia.org/john-j-croat) at [General Motors](https://www.edgepedia.org/general-motors) independently discovered the same Nd₂Fe₁₄B phase, apparently within weeks of Sagawa in early 1982, and both announced at the Pittsburgh conference in November 1983.[12](https://www.nature.com/articles/d42473-023-00333-z) The two products serve different purposes: Sagawa's sintering process made stronger magnets, with twice the strength of samarium-cobalt, while Croat's melt-spinning method allowed a cheaper manufacturing process and a wider range of shapes, notably thin-walled ring magnets ideal for small motors.[12](https://www.nature.com/articles/d42473-023-00333-z) Unit for unit, Sagawa's sintered magnet is significantly stronger but more expensive than Croat's bonded product.[10](https://www.bbc.co.uk/news/science-environment-60205351)\n\n## Patents and commercialization\n\nSagawa holds over 60 global patents.[1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942) Both Sumitomo and General Motors filed patents shortly after the early-1982 invention, apparently within weeks of each other; General Motors ended up with the composition patents in North America, and Sumitomo in Japan and Europe.[14](https://spectrum.ieee.org/the-men-who-made-the-magnet-that-made-the-modern-world) The companies resolved the conflict through a cross-licensing agreement split by particle size: Sumitomo held the rights to magnets with particle size greater than one micron, General Motors to less than one micron, allowing both to market worldwide.[14](https://spectrum.ieee.org/the-men-who-made-the-magnet-that-made-the-modern-world)\n\nTwo product lines resulted: sintered magnets commercialized by Sumitomo Special Metals, and resin-bonded and hot-deformed magnets from rapidly solidified alloys commercialized by Magnequench of General Motors.[8](https://www.kva.se/evenemang/invention-industrialization-and-basic-research-of-the-nd-fe-b-magnets/)\n\n## By the numbers\n\nOver 200,000 tonnes of Nd₂Fe₁₄B are produced each year, with a sales volume equivalent to about 30 billion dollars.[8](https://www.kva.se/evenemang/invention-industrialization-and-basic-research-of-the-nd-fe-b-magnets/) The European Patent Office gives two different shares for the material in the magnet market: around 95% of all permanent magnets on the market today by value, and, in its 2024 award release, some 60% of all permanent magnets.[16](https://www.epo.org/en/news-events/european-inventor-award/meet-the-finalists/masato-sagawa) • [1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942)\n\nApplications have shifted over time. Early uses included hard disk drives, cell phones, automobiles, and home appliances; the current major applications are the traction motors of hybrid and pure electric vehicles, which require higher coercivity against thermal demagnetization, plus established wind-turbine permanent-magnet generators, and general uses needing small powerful magnets such as robots, automation systems, and domestic appliances.[4](https://www.sciencedirect.com/science/article/pii/S1567271918300039) • [11](https://sj.jst.go.jp/news/202312/n1204-01p.html) • [9](https://qeprize.org/winners/the-worlds-strongest-permanent-magnet)\n\n## Later career and honors\n\nIn 1988 Sagawa founded Intermetallics Co. Ltd in Kyoto and became its president, and in 2013 he founded NDFEB Corporation for consultation services; he also works as a consultant for [Daido Steel](https://www.edgepedia.org/daido-steel) on technology that improves magnetic energy density and reduces dysprosium use.[7](https://qeprize.org/winners/dr-masato-sagawa) He was appointed a distinguished invited university professor at Tohoku University in 2019.[5](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/)\n\nHis honors trace the recognition of the invention: the Osaka Prize in 1984, the American Physical Society International Prize for New Materials in 1986, the 2012 [Japan Prize](https://www.edgepedia.org/japan-prize) for developing the world's highest performing Nd-Fe-B type permanent magnet and contributing to energy conservation, and the [Queen Elizabeth Prize for Engineering](https://www.edgepedia.org/queen-elizabeth-prize-for-engineering) in February 2022, awarded to Sagawa alone for the discovery, development, and global commercialization of the world's most powerful permanent magnet.[7](https://qeprize.org/winners/dr-masato-sagawa) • [9](https://qeprize.org/winners/the-worlds-strongest-permanent-magnet) • [17](https://www.japan.go.jp/kizuna/2022/04/magnet_innovation.html) Later awards he shared with Croat: the IEEE 2022 Medal for Environmental and Safety Technologies and the Honda Prize 2023.[10](https://www.bbc.co.uk/news/science-environment-60205351) • [11](https://sj.jst.go.jp/news/202312/n1204-01p.html) In 2024, at age 80, he received the European Inventor Award.[1](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942)\n\n## References\n\n1. [European Patent Office — Japanese scientist wins the European Inventor Award 2024](https://www.epo.org/en/news-events/press-centre/press-release/2024/1181942)\n2. [Nd-Fe-B-Based Sintered Magnets, Springer Nature Link](https://link.springer.com/rwe/10.1007/978-981-19-9644-3_36-1)\n3. [The Japan Prize Foundation — 2012 Japan Prize citation for Dr. Masato Sagawa](https://www.japanprize.jp/en/prize_past_2012_prize02.html)\n4. [Advances in Nd-Fe-B Based Permanent Magnets, Handbook of Magnetic Materials Vol. 27 (2018)](https://www.sciencedirect.com/science/article/pii/S1567271918300039)\n5. [Kobe University News — A beginner's question led to breakthrough](https://www.kobe-u.ac.jp/en/news/article/20250305-66462/)\n6. [The Japan Prize Foundation — 2012 Achievements Profile: Masato Sagawa](https://www.japanprize.jp/data/prize/2012/e_2_achievements.pdf)\n7. [Queen Elizabeth Prize for Engineering — Dr Masato Sagawa profile](https://qeprize.org/winners/dr-masato-sagawa)\n8. [Kungl. Vetenskapsakademien — NdFeB magnets: invention, industrialization and basic research](https://www.kva.se/evenemang/invention-industrialization-and-basic-research-of-the-nd-fe-b-magnets/)\n9. [Queen Elizabeth Prize for Engineering — The World's Strongest Permanent Magnet](https://qeprize.org/winners/the-worlds-strongest-permanent-magnet)\n10. [BBC News — Queen Elizabeth Prize for Engineering honours magnet pioneer](https://www.bbc.co.uk/news/science-environment-60205351)\n11. [Science Japan — The Honda Prize 2023 awarded to Dr. Masato Sagawa and Dr. John J. Croat](https://sj.jst.go.jp/news/202312/n1204-01p.html)\n12. [Nature Research Custom — Inventing the world's strongest magnet](https://www.nature.com/articles/d42473-023-00333-z)\n13. [National laboratory technical report — Emerging Magnetic Materials for Electric Vehicle Drive Motors](https://docs.nlr.gov/docs/fy24osti/88583.pdf)\n14. [IEEE Spectrum — The Magnet That Made the Modern World](https://spectrum.ieee.org/the-men-who-made-the-magnet-that-made-the-modern-world)\n15. [Daido Steel — インタビュー｜佐川顧問スペシャルサイト](http://www.daido.co.jp/neodymium_sagawa/interview/)\n16. [European Patent Office — Masato Sagawa, European Inventor Award finalist](https://www.epo.org/en/news-events/european-inventor-award/meet-the-finalists/masato-sagawa)\n17. [JapanGov Kizuna — Making a Big Leap in Magnet Innovation](https://www.japan.go.jp/kizuna/2022/04/magnet_innovation.html)\n\n---\n*Topic: Encyclopedia › Physical world and mathematics › Physical and mathematical scientists › Physicists and astronomers › Researchers in condensed matter physics and quantum materials › Magnetism and magnetic materials*\n\n*Initially written Oct 10, 2026 · Edited: Oct 11, 2026; Oct 12, 2026; Oct 15, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/masato-sagawa", "markdown_url": "https://www.edgepedia.org/masato-sagawa.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Masato Sagawa\", Edgepedia (EdgeChat), https://www.edgepedia.org/masato-sagawa. Edgepedia Community License 1.0.", "credit_md": "\"[Masato Sagawa](https://www.edgepedia.org/masato-sagawa)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/masato-sagawa](https://www.edgepedia.org/masato-sagawa). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Masato Sagawa\", Edgepedia (EdgeChat), https://www.edgepedia.org/masato-sagawa. Edgepedia Community License 1.0.", "speakable": "Masato Sagawa, born 1943 in Tokushima, Japan, is a Japanese materials scientist who invented the sintered Nd-Fe-B permanent magnet in 1982, now used in electric-vehicle motors and wind turbines." }