Growth of rectangular hollow tube crystals with rutile-type structure in supercritical fluids

18th APS-SCCM; 24th AIRAPT

Niwa, K.^1 ; Ikegaya, H.^2 ; Taguchi, T.^2 ; Muto, S.^3 ; Tokunaga, T.^2 ; Hasegawa, M.^1

Department of Crystalline Materials Science, Nagoya University, Furo-cho, Chikusa, Nagoya

464-8603, Japan^1

Department of Materials Science and Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya

464-8603, Japan^2

EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa, Nagoya

4648603, Japan^3

关键词: Experimental development;    Extraction process;    Growth mechanisms;    Laser-heated diamond anvil cells;    Material science;    Preferential growth;    Rutile-type structures;    Synthesis procedure;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/2/022007/pdf
DOI  :  10.1088/1742-6596/500/2/022007

来源: IOP

【 摘 要 】

Super critical fluids are well known as suitable solvents for dissolution and extraction processes, because it exhibits extreme high solubility and reactivity. However further experimental development using supercritical fluid would offer new insight in material science, especially the synthesis and crystal growth of novel materials. We report the successful growth of single crystals with the rutile-type structure (TiO2, Co-doped TiO2, SiO2, GeO2and SnO2) in supercritical fluids (water or oxygen) using a laser heated diamond-anvil cell up to a pressure of 7 GPa. The resultant product showed the rectangular hollow tube morphology, a several tens of microns in length and a wall thickness of less than 500 nm. TEM analyses demonstrated that this rectangular hollow tube single crystals were surrounded by the {110} faces and grown along the [001] direction. The preferential growth of {110} faces is consistent with the lowest surface energy of {110} faces of the rutile-type structure. In addition, the rapid cooling rate in LHDAC and high solubility of supercritical fluids also play an important role for the formation of the rectangular hollow tube. The details of the synthesis procedure, characterization and growth mechanism are discussed in this paper.