identification of the metastable phase during solidification from the undercooled YFeO melt by fast X-ray diffractometry at 250 Hz
250Hzの高速X線回折法による過冷却YFeO融体の凝固中に現れる準安定相のその場同定
長汐 晃輔*; 栗林 一彦*; Vijaya Kumar, M. S.*; 庭田 健司*; 日比谷 孟俊*; 水野 章敏*; 渡辺 匡人*; 片山 芳則
Nagashio, Kosuke*; Kuribayashi, Kazuhiko*; Vijaya Kumar, M. S.*; Niwata, Kenji*; Hibiya, Taketoshi*; Mizuno, Akitoshi*; Watanabe, Masahito*; Katayama, Yoshinori
ReFeO(Re=YとLu)が無容器で凝固する途中での準安定相をその場で同定するため、放射光源を用いた250Hzでの時分割X線回折(XRD)実験を行った。準安定相は、最初に過冷却状態のYFeOの融体から凝固し、最終的には短いリカレッセンスの間(0.035s)に安定な斜方晶YFeO相へと相変態する。凝固後の試料の粉末X線回折では準安定相を検出できないが、今回測定に成功したYFeOの準安定相の回折パターンは、準安定六方晶LuFeO相と一致した。
A time-resolved X-ray diffraction (XRD) experiment at 250 Hz using a synchrotron radiation source was carried out during the containerless solidification of ReFeO (Re=Y and Lu) in order to identify the metastable phase . The metastable phase solidified primarily from the undercooled YFeO melt finally transformed to the stable orthorhombic YFeO phase during the short period of recalescence (0.035 s). Although the metastable phase could not be detected in the as-solidified sample by the powder XRD, the successfully obtained diffraction pattern of the metastable phase in the YFeO system was consistent with that of the metastable hexagonal LuFeO phase.