Structural phase transition of TmGa2 at high pressure
作者:U. Schwarz、S. Bräuninger、Yu. Grin、K. Syassen
DOI:10.1016/s0925-8388(96)02492-9
日期:1996.11
We have investigated the structural properties of the intermetallic compound TmGa2 under hydrostatic pressures up to 45 GPa by means of X-ray powder diffraction in diamond anvil cells. The orthorhombic low-pressure modification of the KHg2 (CeCu2) type undergoes a structural phase transition at 21(3) GPa into a high-pressure modification of the AlB2 structure type. TB-LMTO-ASA calculations and use of the electron localization function confirm that the structural change from a three-dimensional gallium network to a layered structure is associated with a transition from a tetrahedral homonuclear gallium network to a trigonal planar one.