2011 年 53 巻 1 号 p. 25-29
The crystal structure of η-Al(OH)3, which is a high pressure form of gibbsite (γ-Al(OH)3), was solved by single crystal X-ray diffraction and molecular dynamics simulations. The phase transition mechanism is considered to be the layer-shift type, which may frequently occur for layered hydrous minerals with non-close packing structure of oxygens. The layer-shift transition involves breaking and recombination of hydrogen bonds so that the activation energy of phase transition could directly relate to the strength of hydrogen bonds.