Ce-Zr compounds such as Cc0.68Zr0.3202 solid solution, Ce/Zr nitrate and CeO2/ZrO2 were added into γ-alumina-based slurries, which were then loaded on FeCrAl foils pretreated at 950℃ and 1100℃. The microstructures ...Ce-Zr compounds such as Cc0.68Zr0.3202 solid solution, Ce/Zr nitrate and CeO2/ZrO2 were added into γ-alumina-based slurries, which were then loaded on FeCrAl foils pretreated at 950℃ and 1100℃. The microstructures and adhesion performance between the substrates and the washcoats were measured by SEM, BET surface area, ultrasonic vibration and thermal shock test. The results show that the addition of Ce0.68Zr0.32O2 solid solution, Ce/Zr nitrate and CeO2/ZrO2 into the slurries can improve γ-Al2O3-based washcoat adhesion on FeCrAl foils. Furthermore, ceria-zirconia solid solution increases the adhesion of the washcoat on the surface of an FeCrAl foil than the two others. The specific surface area of this washcoat remains about 4345 m^2/g and the weight loss is below 4.0% even after aging test of 10% steam-containing air at 1050℃ for 20 h.展开更多
The structure and magnetic properties of Ce 2Co 17-xM x(M=Ga,Al and Si) compounds for M concentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements. The experimental results show...The structure and magnetic properties of Ce 2Co 17-xM x(M=Ga,Al and Si) compounds for M concentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements. The experimental results show that the Curie temperatures and Co spontaneous magnetization decrease significantly with increasing the addition of non-magnetic substitutional atoms, and that Si which has a minimum solid solubility in Ce 2Co 17 causes a largest reduction of Curie temperature, spontaneous magnetization and moment per Co atom compared with Ga and Al.展开更多
采用第一性原理对C-Ce二元系CCe、C_2Ce、C_3Ce_23种化合物的晶体结构进行优化,并对它们的生成焓、结合能、电子结构、弹性性能及德拜温度进行了计算分析。对生成焓、结合能、德拜温度的计算结果表明:3种化合物的生成焓、结合能均为负值...采用第一性原理对C-Ce二元系CCe、C_2Ce、C_3Ce_23种化合物的晶体结构进行优化,并对它们的生成焓、结合能、电子结构、弹性性能及德拜温度进行了计算分析。对生成焓、结合能、德拜温度的计算结果表明:3种化合物的生成焓、结合能均为负值,且C_3Ce_2的生成焓、结合能值最低依次为-0.858 7 e V/atom,-6.999 0 e V/atom;德拜温度最高,为376 K,具有最强的化合物形成能力。电子结构的分析表明:C_3Ce_2成键电子中C的2s、2p与Ce的5p、5d杂化作用明显,且具有较强的共价性,结构稳定性最好。体模量(B)、弹性模量(E)、泊松比(ν)、理论硬度(Hv)等计算结果表明:C2Ce不符合力学稳定性标准;CCe为延性、各向异性;C_3Ce_2为轻微脆性、各向同性,C_3Ce_2理论硬度远大于CCe,具有较好的力学稳定性。展开更多
基金[The work was financially supported by the National Key Basic Research Program of China ("973")(No. 2004CB719503).]
文摘Ce-Zr compounds such as Cc0.68Zr0.3202 solid solution, Ce/Zr nitrate and CeO2/ZrO2 were added into γ-alumina-based slurries, which were then loaded on FeCrAl foils pretreated at 950℃ and 1100℃. The microstructures and adhesion performance between the substrates and the washcoats were measured by SEM, BET surface area, ultrasonic vibration and thermal shock test. The results show that the addition of Ce0.68Zr0.32O2 solid solution, Ce/Zr nitrate and CeO2/ZrO2 into the slurries can improve γ-Al2O3-based washcoat adhesion on FeCrAl foils. Furthermore, ceria-zirconia solid solution increases the adhesion of the washcoat on the surface of an FeCrAl foil than the two others. The specific surface area of this washcoat remains about 4345 m^2/g and the weight loss is below 4.0% even after aging test of 10% steam-containing air at 1050℃ for 20 h.
文摘The structure and magnetic properties of Ce 2Co 17-xM x(M=Ga,Al and Si) compounds for M concentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements. The experimental results show that the Curie temperatures and Co spontaneous magnetization decrease significantly with increasing the addition of non-magnetic substitutional atoms, and that Si which has a minimum solid solubility in Ce 2Co 17 causes a largest reduction of Curie temperature, spontaneous magnetization and moment per Co atom compared with Ga and Al.
文摘采用第一性原理对C-Ce二元系CCe、C_2Ce、C_3Ce_23种化合物的晶体结构进行优化,并对它们的生成焓、结合能、电子结构、弹性性能及德拜温度进行了计算分析。对生成焓、结合能、德拜温度的计算结果表明:3种化合物的生成焓、结合能均为负值,且C_3Ce_2的生成焓、结合能值最低依次为-0.858 7 e V/atom,-6.999 0 e V/atom;德拜温度最高,为376 K,具有最强的化合物形成能力。电子结构的分析表明:C_3Ce_2成键电子中C的2s、2p与Ce的5p、5d杂化作用明显,且具有较强的共价性,结构稳定性最好。体模量(B)、弹性模量(E)、泊松比(ν)、理论硬度(Hv)等计算结果表明:C2Ce不符合力学稳定性标准;CCe为延性、各向异性;C_3Ce_2为轻微脆性、各向同性,C_3Ce_2理论硬度远大于CCe,具有较好的力学稳定性。
