Cd-Yb近似結晶の低温高圧下で現れる多様な構造秩序
2007 年 49 巻 1 号 p. 45-50
詳細
2007 年 49 巻 1 号 p. 45-50
High pressure and low temperature X-ray diffraction study of Cd-Yb 1/1 crystalline approximant revealed that the innermost part of the atomic clusters of Cd4 tetrahedra exhibit various types of orientational ordering sensitively depending on pressure and temperature. Five ordered phases appeared in a P-T span up to 5.2 GPa and down to 10 K. The propagation direction of ordering alternated from [1 10] to ‹ 111› at about 1.0 GPa and again to [110] at 3.5-4.3 GPa. The primarily ordered phases that appeared by cooling to 210-250 K between 1-5.2 GPa further transformed to finely ordered ones at 120-155 K. Coexistence of two different types of interaction between Cd4 tetrahedra cause these complicated phase behavior.
