Lead niobium titanate, Pb(Nb,Ti)O3, thin films were prepared on various substrates by metalorganic chemical vapor deposition from the Pb(C11H19O2)2–Nb(O⋅C2H5)5–Ti(O⋅i-C3H7)4–O2 system. Polycrystalline films with (111) orientation and epitaxially grown films with c-axis orientation were deposited on the (111)Pt/Ti/SiO2(100)Si and PbTiO3/(111)Pt/Ti/SiO2/(100)Si substrates, and (100)SrRuO3//(100)LaAlO3 substrate, respectively, at 620 °C. Nb content in the film can be controlled only by changing the input gas flow rate of Nb(O⋅C2H5)5 under the excess gas flow rate of Pb(C11H19O2)2. The composition of the film was independent of the deposition temperature from 400 to 620 °C. The single phase of Pb(Nb,Ti)O3 was deposited up to the Nb content of about 5 at % and pyrochlore phase was codeposited above this Nb content. Leakage current density decreased with the increasing Nb content in the film up to 6.5 at %. Coercive field (Ec) of the film was about 130 kV/cm and was independent of the Nb content and the kinds of substrates. On the other hand, the remanent polarization (Pr) of the film on the (111)Pt/Ti/SiO2/(100)Si substrate increased from 9 to 29 μC/cm2 with the increasing Nb content from 2.1 to 4.8 at %. Pr of the film on the (100)SrRuO3//(100)LaAlO3 substrate was smaller than those of the (111)Pt/Ti/SiO2/Si and PbTiO3/(111)Pt/Ti/SiO2/Si substrates.

Zirconia films stabilized by Y2O3 were deposited by metal-organic chemical vapor techniques onto various crystalline substrates. Y2O3, ZrO2 and mixtures of these two were deposited and characterized. The deposition rate, the film composition and the structure could be systematically varied through the Y(C11H19O2)3, Zr(O·t-C4H9)4 and O2 source gas ratios and the substrate temperature. The Y/Zr ratio could be adjusted by controlling the ratio in Y(C11H19O2)3 to Zr(O·t-C4H9)4 partial pressures. However, the Y/Zr ratio was found to be smaller than that estimated based on the deposition rates of unmixed Y2O3 and ZrO2 films. The activation energy of the Y2O3 component in YSZ film growth was similar to that of the ZrO2 component in YSZ films. These YSZ values were more than 4 times larger than those of unmixed Y2O3 or ZrO2 films.

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A system has been developed to improve the efficiency of maintenance work while decreasing the radiation exposure of maintenance personnel in nuclear power plants. The input data for dose rate calculation are automatically generated by using computer-aided design data. Changes for the input data corresponding to the progress of maintenance work, such as installation of a radiation shield and removal of a component, are easily input interactively on a graphical user interface (GUI). A new method was proposed which searches the sets of source and detector points between which gamma-ray attenuation is changed by the component movement. The calculation is performed only for the changed sets, so that the change of the three-dimensional dose rate distribution is calculated rapidly according to the work progress. The dose rate distribution and the radiation exposure of maintenance personnel are displayed three-dimensionally in colour with plant components and pipes on the GUI.

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