Shohei Yamaguchi's research while affiliated with Tokyo University of Science and other places

... Thus, the slope value of the conductivity against P O2 reflects electron or hole conduction or electronion mixed conduction. [32][33][34] The slope value in this study is estimated to be −0.004, which indicates the ion conduction at 300 K. 34) Figure 3 shows the O 1s core level PES spectrum of the BaTiO 3À thin film. ...

... However, the small peak at around 9 eV in the BPY XPS spectrum is not present in the calculated DOS. This peak is unlikely to be the Pr-4f peak since photoelectron spectroscopy data of BaPrO 3 from literature 11,12 reported Pr states to be located near the top of the O states in the valence band. This discrepancy may have been due to XPS being a surface sensitive technique (∼5 nm), whereas the calculated DOS was for the bulk. ...

... Conduction properties of undoped TiO 2 thin film with anatase or rutile structure can be controlled from an insulator phase to semiconductor or metal phase by substitution of different ion on the Ti 4+ site. [1][2][3][4][5][6][7][8][9][10] Typical materials are Nb 5+ -doped TiO 2 (Ti 1Àx Nb x O 2 ), [2][3][4][5] Ta 5+ -doped TiO 2 (Ti 1Àx -Ta x O 2 ) 6) and Co-doped TiO 2 (Ti 1Àx Co x O 2À ). 7,8) Hitosugi et al. has reported that the anatase-type Ti 0.95 Ta 0.05 O 2 epitaxial thin film prepared by pulsed laser deposition exhibits a low resistivity of 2:5 Â 10 À4 Ω cm, carrier density of 1:4 Â 10 21 cm −3 and high internal transmittance of 95% in the visible light region at room temperature (R.T.). ...

... Thus, the slope value of the conductivity against P O2 reflects electron or hole conduction or electronion mixed conduction. [32][33][34] The slope value in this study is estimated to be −0.004, which indicates the ion conduction at 300 K. 34) Figure 3 shows the O 1s core level PES spectrum of the BaTiO 3À thin film. ...