Polymer-assisted deposition technique has been used to deposit Al2O3 and N-doped Al2O3 （AION） thin films on Si（100） substrates. The chemical compositions, crystallinity, and thermal conductivity of the as-grown fi...Polymer-assisted deposition technique has been used to deposit Al2O3 and N-doped Al2O3 （AION） thin films on Si（100） substrates. The chemical compositions, crystallinity, and thermal conductivity of the as-grown films have been characterized by X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and 3-omega method, respectively. Amorphous and polycrystalline Al2O3 and AlON thin films have been formed at 700 ℃ and 1000 ℃. The thermal conductivity results indicated that the effect of nitrogen doping on the thermal conductivity is determined by the competition of the increase of Al-N bonding and the suppression of crystallinity. A 67% enhancement in thermal conductivity has been achieved for the samples grown at 700 ℃, demonstrating that the nitrogen doping is an effective way to improve the thermal performance of polymer-assisted-deposited Al2O3 thin films at a relatively low growth temperature.展开更多
为了探求过渡金属催化剂对催化合成储氢材料Na Al H4效果的影响,本文采用第一性原理方法研究了多种金属原子取代Al(111)表面铝原子形成的合金表面对氢的催化分解的影响.计算结果表明,Sc,V,Fe,Ti原子掺杂的表面对氢分子分解具有催化作用...为了探求过渡金属催化剂对催化合成储氢材料Na Al H4效果的影响,本文采用第一性原理方法研究了多种金属原子取代Al(111)表面铝原子形成的合金表面对氢的催化分解的影响.计算结果表明,Sc,V,Fe,Ti原子掺杂的表面对氢分子分解具有催化作用.H2在对应的掺杂表面催化分解所需要的活化能分别为0.54 eV,0.29 eV,0.51 eV,0.12 eV.H原子在Sc,V,Ti掺杂表面扩散需要的活化能分别为0.51 eV,0.66 eV,0.57 eV.同时,过渡金属掺杂在Al表面时倾向于分散分布,增加掺杂表面的掺杂原子个数,掺杂表面的催化效果体现为单个掺杂过渡金属原子的催化效果.本研究将为金属掺杂Al(111)表面催化加氢合成Na Al H4提供理论参考.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60976061 and 11028409)
文摘Polymer-assisted deposition technique has been used to deposit Al2O3 and N-doped Al2O3 （AION） thin films on Si（100） substrates. The chemical compositions, crystallinity, and thermal conductivity of the as-grown films have been characterized by X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and 3-omega method, respectively. Amorphous and polycrystalline Al2O3 and AlON thin films have been formed at 700 ℃ and 1000 ℃. The thermal conductivity results indicated that the effect of nitrogen doping on the thermal conductivity is determined by the competition of the increase of Al-N bonding and the suppression of crystallinity. A 67% enhancement in thermal conductivity has been achieved for the samples grown at 700 ℃, demonstrating that the nitrogen doping is an effective way to improve the thermal performance of polymer-assisted-deposited Al2O3 thin films at a relatively low growth temperature.
