Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
J Am Chem Soc. 2012 May 30;134(21):8782-5. doi: 10.1021/ja302465c. Epub 2012 May 18.
Epitaxial thin films of titanium perovskite oxyhydride ATiO(3-x)H(x) (A = Ba, Sr, Ca) were prepared by CaH(2) reduction of epitaxial ATiO(3) thin films deposited on a (LaAlO(3))(0.3)(SrAl(0.5)Ta(0.5)O(3))(0.7) substrate. Secondary ion mass spectroscopy detected a substantial amount and uniform distribution of hydride within the film. SrTiO(3)/LSAT thin film hydridized at 530 °C for 1 day had hydride concentration of 4.0 × 10(21) atoms/cm(3) (i.e., SrTiO(2.75)H(0.25)). The electric resistivity of all the ATiO(3-x)H(x) films exhibited metallic (positive) temperature dependence, as opposed to negative as in BaTiO(3-x)H(x) powder, revealing that ATiO(3-x)H(x) are intrinsically metallic, with high conductivity of 10(2)-10(4) S/cm. Treatment with D(2) gas results in hydride/deuteride exchange of the films; these films should be valuable in further studies on hydride diffusion kinetics. Combined with the materials' inherent high electronic conductivity, new mixed electron/hydride ion conductors may also be possible.
钙氢化物还原外延 ATiO(3) 薄膜，制备钛钙钛矿氧氢化物 ATiO(3-x)H(x) (A = Ba, Sr, Ca)外延薄膜。在 (LaAlO(3))(0.3)(SrAl(0.5)Ta(0.5)O(3))(0.7)衬底上沉积外延 ATiO(3) 薄膜。二次离子质谱检测到薄膜内有大量且均匀分布的氢化物。SrTiO(3)/LSAT 薄膜在 530 °C 下氢化 1 天，氢化物浓度为 4.0×10(21)原子/cm(3)(即 SrTiO(2.75)H(0.25))。所有 ATiO(3-x)H(x) 薄膜的电阻率均表现出金属（正）温度依赖性，与 BaTiO(3-x)H(x) 粉末的负温度依赖性相反，表明 ATiO(3-x)H(x) 本质上是金属的，电导率高达 10(2)-10(4) S/cm。与 D(2)气体处理导致薄膜的氢化物/氘化物交换；这些薄膜在进一步研究氢化物扩散动力学方面应该是有价值的。结合材料固有的高电子电导率，也可能开发出新型混合电子/氢化物离子导体。
