Isothermal transient ionic current as a characterization technique for iontransport in Ta2O5

The Isothermal Transient Ionic Current (ITIC) technique was applied to beta -Ta2O5 samples made by chemical vapor deposition. The mobility, conductivit y, and number of protons in the material could be extracted from the measur ements. Li ions were intercalated electrochemically into the beta-Ta2O5 and it was found that the ITIC method could separate the contribution from pro ton and Li ion conduction in such a way that the mobilities of both species could be extracted. Furthermore, the lattice-gas model [A. J. Berlinsky, W . G. Unruh, W. R. McKinnon, and R. R. Haering, Solid State Commun. 31, 135 (1979)] was employed to describe the Li interaction process. This model sho wed that the Li ions tended to distribute uniformly, rather then to attract each other and form clusters in the material. (C) 1999 American Institute of Physics. [S0021-8979(99)00812-9].