Single-crystal neutron diffraction study of pseudo single crystal prepared from microcrystalline powder

磁場配向擬単結晶の中性子回折による研究

木村 史子*; 木村 恒久*; 松本 賢司*; 目時 直人   

Kimura, Fumiko*; Kimura, Tsunehisa*; Matsumoto, Kenji*; Metoki, Naoto

L-アラニン擬単結晶を三次元磁場配向により作成し、紫外線硬化性樹脂によって固めた。直径約8mm,高さ10mmの円筒形試料を中性子回折によって測定した。極点図は(120),(040)、及び(002)面でシャープなピークを示し、三次元配向を実証することができた。また、測定された積分強度は強度計算結果と良い一致を示した。本研究は大きな結晶が利用できない物質について、三次元磁場配向擬単結晶を育成することによって中性子回折による結晶構造解析が実現できる可能性について明らかにした。

Single-crystal neutron diffraction analysis of an L-alanine pseudo single crystal (PSC, a composite in which microcrystals are aligned three-dimensionally) prepared from its powder is presented. Microcrystals of L-alanine were suspended in an ultraviolet-curable resin precursor and subjected to three-dimensional magnetic alignment, followed by consolidation of the resin precursor to fix the achieved alignment. A cylindrical PSC of diameter ca. 8 mm and height 10 mm was obtained and then subjected to neutron diffraction measurements. Pole figures measured at (040), (120), and (002) planes showed sharp peaks, demonstrating three-dimensional alignment of microcrystals. Scans were performed for 31 diffraction peaks whose intensities showed good agreement with calculation results. The present study showed the potential use of the PSC method in single-crystalneutron diffraction analysis when a large crystal is not available.