Nanostructured zirconia top coat was deposited by air plasma spray and NiCoCrAlTaY bond coat was deposited on Ni substrate by low pressure plasma spray.Nanostructured and conventional thermal barrier coatings were hea...Nanostructured zirconia top coat was deposited by air plasma spray and NiCoCrAlTaY bond coat was deposited on Ni substrate by low pressure plasma spray.Nanostructured and conventional thermal barrier coatings were heat-treated at temperature varying from 1050 to 1 250oC for 2-20 h.The results show that obvious grain growth was found in both nanostructured and conventional thermal barrier coatings(TBCs)after high temperature heat treatment.Monoclinic/tetragonal phases were transformed into cubic phase in the agglomerated nano-powder after calcination.The cubic phase content increased with increasing calcination temperature.Calcination of the powder made the yttria distributed on the surface of the nanocrystalline particles dissolve in zirconia when grains grew.Different from the phase constituent of the as-sprayed conventional TBC which consisted of diffusionlesstransformed tetragonal,the as-sprayed nanostructured TBC consisted of cubic phase.展开更多
We report room-temperature electroluminescence (EL) from as-deposited amorphous-Si/silicon oxynitride multilayer structure prepared by plasma enhanced chemical vapor deposition. We prepared 8-period a-Si/SiOxNy multil...We report room-temperature electroluminescence (EL) from as-deposited amorphous-Si/silicon oxynitride multilayer structure prepared by plasma enhanced chemical vapor deposition. We prepared 8-period a-Si/SiOxNy multilayer with thickness of 4 nm both for the Si and SiOxNy sublayers. The EL spectral profile exhibits some obviously modulated features upon the barrier material. By adjusting the nitride/oxygen ratio in the barrier layer, the EL peak position can be tuned from 750 nm to 695 nm. From the result of the Raman and Fourier transform infrared results, the EL is attributed to the radiative recombination of electrons and holes in luminescent centers related to the interface. The different interface characteristics induce the shift of EL peak position.展开更多
基金Project(1343-77212)supported by the Innovation Program for Graduate Students of Central South University,China
文摘Nanostructured zirconia top coat was deposited by air plasma spray and NiCoCrAlTaY bond coat was deposited on Ni substrate by low pressure plasma spray.Nanostructured and conventional thermal barrier coatings were heat-treated at temperature varying from 1050 to 1 250oC for 2-20 h.The results show that obvious grain growth was found in both nanostructured and conventional thermal barrier coatings(TBCs)after high temperature heat treatment.Monoclinic/tetragonal phases were transformed into cubic phase in the agglomerated nano-powder after calcination.The cubic phase content increased with increasing calcination temperature.Calcination of the powder made the yttria distributed on the surface of the nanocrystalline particles dissolve in zirconia when grains grew.Different from the phase constituent of the as-sprayed conventional TBC which consisted of diffusionlesstransformed tetragonal,the as-sprayed nanostructured TBC consisted of cubic phase.
基金supported by the National Natural Science Foundation of China (Grant No. 60806046)the Foundation for Distinguished Young Talents in Higher Education of Guangdong (Grant Nos. LYM09101,LYM11090 and LYM10099)
文摘We report room-temperature electroluminescence (EL) from as-deposited amorphous-Si/silicon oxynitride multilayer structure prepared by plasma enhanced chemical vapor deposition. We prepared 8-period a-Si/SiOxNy multilayer with thickness of 4 nm both for the Si and SiOxNy sublayers. The EL spectral profile exhibits some obviously modulated features upon the barrier material. By adjusting the nitride/oxygen ratio in the barrier layer, the EL peak position can be tuned from 750 nm to 695 nm. From the result of the Raman and Fourier transform infrared results, the EL is attributed to the radiative recombination of electrons and holes in luminescent centers related to the interface. The different interface characteristics induce the shift of EL peak position.
