Phase transformation and resistivity of dumbbell-like ZnO microcrystals under high pressure

High-pressure Raman spectra and in situ electrical resistivity measurement of the dumbbell-like ZnO microcrystals have been investigated by using the diamond-anvil-cell technique at room temperature. The dumbbell-like ZnO microcrystals were synthesized via a facile solution method under mild conditions. In terms of the Raman results, the dumbbell-like ZnO microcrystals underwent a transition from wurtzite to rock-salt structure with increasing pressure and the phase-transition pressure was about 11.13 GPa. In situ electrical resistivity measurement of the dumbbell-like ZnO microcrystals was performed on a designed diamond anvil cell. The change in electrical resistivity related to the phase structure for the ZnO microcrystals was observed with the applied pressure of up to 34.86 GPa. Moreover, the pressure dependence of the electrical resistivity for the dumbbell-like ZnO microcrystals annealed at different conditions was also investigated. (C) 2008 American Institute of Physics.