2025-09-04 愛媛大学
イメージ図 （アインシュタインの相対性理論をもとにディラックが予言した光のような不思議な電子（ディラック電子）。物質中では例えば砂時計の形をしたバンドと呼ばれる入れ物に入っており、その細い繋目を通って上に行ったり下に行ったりします。）
＜関連情報＞
- https://www.ehime-u.ac.jp/data_relese/pr_20250904_sci/
- https://www.ehime-u.ac.jp/wp-content/uploads/2025/09/pr_20250904_sci.pdf
- https://pubs.acs.org/doi/10.1021/acs.jpclett.5c02197
Universal Features of Magnetic Behavior Originating from Linear Band Dispersion: α-BETS2X and α′-BETS2Y (BETS = Bis(ethylenedithio)tetraselenafulvalene, X = IBr2, I2Br, Y = IBr2, ICl2) 線形分散を持つバンド構造に由来する普遍的な磁性の特徴：α-BETS2X 及びα’-BETS2（BETS =ビス（エチレンジチオ）テトラセレナフルバレン, X = IBr2, I2Br, Y = IBr2, ICl2）
Sakura Hiramoto,Koki Funatsu,Kensuke Konishi,Haruhiko Dekura,Naoya Tajima,and Toshio Naito
The Journal of Physical Chemistry Letters Published: August 26, 2025
DOI:https://doi.org/10.1021/acs.jpclett.5c02197
Abstract
Unpaired electrons located at linear band dispersion (LBD) are exceptional and are called Dirac electrons (DE). They are given attention because of the unique electronic properties such as temperature (T)-independent resistivity, as if they belong to neither metallic nor nonmetallic substances. Meanwhile, universal features in magnetic behavior remain to be discovered. New organic DE systems, α-BETS2X and α′-BETS2Y (BETS = bis(ethylenedithio)tetraselenafulvalene, X = IBr2 and I2Br, Y = IBr2 and ICl2), were investigated using the X-ray single-crystal structural analyses, electrical resistivity and magnetic susceptibility (χ) measurements, and band structure calculations. They all exhibited an approximately linear T-dependence of χ, which was directly related to the LBD based on our proposed models. The findings will turn scientists’ attention to the physical properties of organic DE at ambient temperature, as dynamics of DE have recently garnered increasing interest.
