Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms

核スピン偏極化試料での偏極中性子回折による構造解析法の開発

三浦 大輔*; 熊田 高之   ; 関根 由莉奈   ; 元川 竜平   ; 中川 洋   ; 大場 洋次郎  ; 大原 高志   ; 高田 慎一  ; 廣井 孝介  ; 森川 利明*; 河村 幸彦*; 大石 一城*; 鈴木 淳市*; 宮地 義之*; 岩田 高広*

Miura, Daisuke*; Kumada, Takayuki; Sekine, Yurina; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Ohara, Takashi; Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; Kawamura, Yukihiko*; Oishi, Kazuki*; Suzuki, Junichi*; Miyachi, Yoshiyuki*; Iwata, Takahiro*

山形大学が原子核物理実験用に開発した結晶試料の核スピン偏極技術を、スピンコントラスト偏極中性子回折測定法に展開し、水素核偏極化されたグルタミン酸を用いて粉末結晶試料中の水素の配向および凝集・分散などの構造情報を抽出できることを実証した。

We developed a spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, namely, the contribution of hydrogen atoms to a crystal structure factor. Crystals of L-glutamic acid were dispersed in a dpolystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy (TEMPO methacrylate) to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.