Structural refinement of the high-pressure phase of aluminum trihydroxide: In-situ high-pressure angle dispersive synchrotron X-ray diffraction and theoretical studies Article

Liu, H, Tse, JS, Hu, J et al. (2005). Structural refinement of the high-pressure phase of aluminum trihydroxide: In-situ high-pressure angle dispersive synchrotron X-ray diffraction and theoretical studies . JOURNAL OF PHYSICAL CHEMISTRY B, 109(18), 8857-8860. 10.1021/jp0501594

cited authors

  • Liu, H; Tse, JS; Hu, J; Liu, Z; Wang, L; Chen, J; Weidner, DJ; Meng, Y; Häusermann, D; Mao, HK

authors

abstract

  • In-situ high-pressure synchrotron angle-dispersive X-ray diffraction for gibbsite (aluminum trihydroxide) was performed at room temperature up to 20 GPa. A pressure-induced phase transition was observed at 2.6 GPa. The new high-pressure phase can be recovered at ambient pressure. Rietveld refinement shows that the new phase of Al(OH) 3 has an orthorhombic structure, spacegroup Pbca, and the lattice parameters at ambient condition are a = 868.57(5) pm, b = 505.21(4) pm, c = 949.54(6) pm, V = 416.67(6) × 10 6 pm 3 with Z = 8. The compressibility of gibbsite and the high-pressure polymorph was analyzed, and their bulk moduli were estimated as 49.8 ±1.8 and 81.0 ± 5.2 GPa, respectively. First-principles calculations of the high-pressure phase were performed to determine the hydrogen positions and to confirm the structural stability of the new phase. © 2005 American Chemical Society.

publication date

  • May 12, 2005

published in

Digital Object Identifier (DOI)

start page

  • 8857

end page

  • 8860

volume

  • 109

issue

  • 18