Pressure-induced amorphization and polyamorphism in one-dimensional   single crystal TiO2 nanomaterials
  The structural phase transitions of single crystal TiO2-B nanoribbons were investigated in-situ at high-pressure using the synchrotron X-ray diffraction and the Raman scattering. Our results have shown a pressure-induced amorphization (PIA) occurred in TiO2-B nanoribbons upon compression, resulting in a high density amorphous (HDA) form related to the baddeleyite structure. Upon decompression, the HDA form transforms to a low density amorphous (LDA) form while the samples still maintain their pristine nanoribbon shape. HRTEM imaging reveals that the LDA phase has an {\alpha}-PbO2 structure with short range order. We propose a homogeneous nucleation mechanism to explain the pressure-induced amorphous phase transitions in the TiO2-B nanoribbons. Our study demonstrates for the first time that PIA and polyamorphism occurred in the one-dimensional (1D) TiO2 nanomaterials and provides a new method for preparing 1D amorphous nanomaterials from crystalline nanomaterials. 
Quanjun Li, Bingbing Liu, Lin Wang, Dongmei Li, Ran Liu, Bo Zou, Tian   Cui, Guangtian Zou, Yue Meng, Ho-kwang Mao, Zhenxian...
cond-mat.mtrl-sci cond-mat.mes-hall physics.geo-ph