Electrical conductivity of BaTi4O9 film prepared by laser chemical vapor deposition method

A BaTi4O9 film was prepared on a Pt/Ti/SiO2/Si substrate by a laser chemical vapor deposition method and was investigated by impedance spectroscopy over ranges of temperature (300–1073 K) and frequency (102–107 Hz). Plots between real and imaginary parts of the impedance (Z′ and Z′′) suggest the presence of two relaxation regimes, which were attributed to grain and grain boundary responses. The conduction of both grains and grain boundaries obeys the Arrhenius format with activation energies of respectively 1.45 and 1.24 eV. The close activation energies indicate that the conduction in BaTi4O9 film is mainly by oxygen vacancies.