An epitaxial ZnO thin film was entirely fabricated by pulsed laser deposition. Both the orientation and the size of the crystallites were studied. The X-ray diffraction （XRD） patterns of the film show strong c-axis ...An epitaxial ZnO thin film was entirely fabricated by pulsed laser deposition. Both the orientation and the size of the crystallites were studied. The X-ray diffraction （XRD） patterns of the film show strong c-axis oriented crystal structure with preferred （002） orientation. The Phi-sca~ XRD pattern confirms that the epitaxiM ZnO exhibits a single- domain wurtzite structure with hexagonal symmetry. In situ high-temperature XRD studies of ZnO thin film show that the crystallite size increases with increasing temperature, and （002） peaks shift systematically toward lower 20 values due to the change of lattice parameters. The lattice parameters show linear increase in their values with increasing temperature.展开更多
The precipitation of MgZn2 phase in aging process of Al-Zn-Mg-Cu alloy forging was characterized qualitatively after transmission electron microscope(TEM)observation,X-ray diffraction phase analysis and the exact meas...The precipitation of MgZn2 phase in aging process of Al-Zn-Mg-Cu alloy forging was characterized qualitatively after transmission electron microscope(TEM)observation,X-ray diffraction phase analysis and the exact measure of lattice parameter.And,the precipitation of the second-phase in aging process was simulated after test the resistivity of the alloy in a continuous heating process and delayed time processing.The results show that when heating in the same rate,the alloy resistivity increases with temperature first,a mutation point appears at 110℃,and the resistivity reaches its peak at 120℃.Then,the resistivity decreases and achieves a minimum at about 170℃.Afterwards,it increases again.The change of resistivity results from a combined effect of the temperature and phase transformation.The volume precipitation of η' phase dominates at about 120℃,and the resistivity of forgings decreases accordingly.When the specimen cools in a furnace at 240℃,the phase transformation finishes basically and the alloy content of Al-matix keeps stable,thus,the alloy resistivity depends on the temperature only.It decreases with temperature and time since the end of precipitation.The higher the temperature is,the bigger it will be.With a big descending rate of the resistivity curve,the time to reach the stable value becomes shorter.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.10490192)
文摘An epitaxial ZnO thin film was entirely fabricated by pulsed laser deposition. Both the orientation and the size of the crystallites were studied. The X-ray diffraction （XRD） patterns of the film show strong c-axis oriented crystal structure with preferred （002） orientation. The Phi-sca~ XRD pattern confirms that the epitaxiM ZnO exhibits a single- domain wurtzite structure with hexagonal symmetry. In situ high-temperature XRD studies of ZnO thin film show that the crystallite size increases with increasing temperature, and （002） peaks shift systematically toward lower 20 values due to the change of lattice parameters. The lattice parameters show linear increase in their values with increasing temperature.
基金Sponsored by the Matching Project of Commission of Scientific and Technical Industry on National Defence(JPPT-×××-1)
文摘The precipitation of MgZn2 phase in aging process of Al-Zn-Mg-Cu alloy forging was characterized qualitatively after transmission electron microscope(TEM)observation,X-ray diffraction phase analysis and the exact measure of lattice parameter.And,the precipitation of the second-phase in aging process was simulated after test the resistivity of the alloy in a continuous heating process and delayed time processing.The results show that when heating in the same rate,the alloy resistivity increases with temperature first,a mutation point appears at 110℃,and the resistivity reaches its peak at 120℃.Then,the resistivity decreases and achieves a minimum at about 170℃.Afterwards,it increases again.The change of resistivity results from a combined effect of the temperature and phase transformation.The volume precipitation of η' phase dominates at about 120℃,and the resistivity of forgings decreases accordingly.When the specimen cools in a furnace at 240℃,the phase transformation finishes basically and the alloy content of Al-matix keeps stable,thus,the alloy resistivity depends on the temperature only.It decreases with temperature and time since the end of precipitation.The higher the temperature is,the bigger it will be.With a big descending rate of the resistivity curve,the time to reach the stable value becomes shorter.
