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This superconducting films of YBa2Cu3O7 have been deposited on SrTiO3 substrates using a home-made hollow cathode magnetron sputtering system. The samples were placed on a variable-temperature target stage of a 200 keV implanter and then bombarded by O+ to different doses. The electrical resistance of the samples and its dependence on both ion dose and temperature were measured in situ. Our experimental results reveal that the resistive behavior is extremely sensitive to ion dose, and the ion damage has a strong effect on the transport properties of these films.

The structures of NaY and ultrastability Y-type (USY) zeolite were studied by positron lifetime spectroscopy.Four lifetimes could be obtained in NaY zeolite,the two larger components were assigned to be o-Ps annihilation in the β cage and supercage respectively.In USY zeolite,however,an additional lifetime component τ5 was observed,which was about 92ns in vacuum with continuous distribution from 39ns to 142ns by the Laplace inversion analysis of lifetime spectrum.The second larger lifetimes τ4 also increased to 14ns,compared to that in NaY zeolite.Existence of the longer lifetimes τ4 and τ5 is due to the porous structure of USY.The positron lifetime in USY zeolite was also measured as a function of air pressure ranging from 0 (vacuum) to 0.1MPa.The most interesting was the variation of the largest components τ5 and I5.They both decreased with increasing air pressure.The results can be explained as follows.First,the oxygen contained in the air could quench the Ps and reduce its lifetime and intensity.Second,the increasing density of air could also increase the probability of o-Ps pick-off annihilation and reduce its formation.These would lead to the decrease of its lifetime and intensity.

Positron annihilation lifetime spectra have been measured for polymer electrolyte poly (ether urethane) (PEU). The variations of the positron annihilation parameters as a function of Li - dopant concentration show that the Li - dopants diffuse mostly into the amorphous regions. The temperature dependances of the o - Ps lifetime and its intensity give the information about the structural transition of PEU and PEU - LiClO4. The relation between the conductivity of PEU - LiClO4 and temperature can be explained by the theory of free volume.