A theoretical model on the solvus line prediction of a film was proposed and applied to a nanogranular Al-Cu system. The calculation results show that the solvus line of solute Cu will markedly lower with the decrease...A theoretical model on the solvus line prediction of a film was proposed and applied to a nanogranular Al-Cu system. The calculation results show that the solvus line of solute Cu will markedly lower with the decrease of grain size, namely, the starting temperature of θ(Al_2Cu) precipitation in a nanogranular Al-Cu film will markedly lower than that of conventional coarse grain alloy with the same Cu concentration, and the precipitation temperatures calculated are comparable with the experimental ones. The theoretical model can be simply used to calculate the starting temperature of precipitation in Al-Cu films under three states: ① films with substrate; ② films without substrate; ③ ultrafine grain bulk alloy. As a result, the model is universal, moreover, can be, in principle, used to predict precipitation temperature in other systems.展开更多
New magnetic air-stable nanogranular Fe thin films of 10 ± 1.2 nm thickness were prepared onto silicon wafers at 150℃ under inert atmosphere by controlled Chemical Vapor Deposition (CVD) of triiron dodecacarbony...New magnetic air-stable nanogranular Fe thin films of 10 ± 1.2 nm thickness were prepared onto silicon wafers at 150℃ under inert atmosphere by controlled Chemical Vapor Deposition (CVD) of triiron dodecacarbonyl (Fe3(CO)12). These thin films, composed of sintered elemental Fe nanoparticles of 4.1 ± 0.7 nm diameter, are protected from air oxidation by a very thin carbon layer. The saturation magnetization of these thin Fe coatings was found to be close to that of bulk iron. The electrical resistivity behavior of the ferromagnetic thin films is similar to that of a semiconductor. In the present manuscript, these Fe thin coatings on Si wafers have been used as a catalyst for synthesizing crystalline carbon nanotubes (CNTs), by CVD using ethylene as a carbon precursor.展开更多
Phosphorus doped（P-doped） nanogranular SiO2 films have been deposited by plasma-enhanced chemical vapor deposition. A high proton conductivity of;.2x10-4S/cm and a large electric double layer（EDL） capacitance of;....Phosphorus doped（P-doped） nanogranular SiO2 films have been deposited by plasma-enhanced chemical vapor deposition. A high proton conductivity of;.2x10-4S/cm and a large electric double layer（EDL） capacitance of;.2μF/cm2 have been obtained. Flexible coplanar-gate EDL thin film transistors（TFTs） gated by P-doped nanogranular SiO2 films are self-assembled on plastic substrates at room temperature. Due to the big EDL capacitance,such TFTs show ultra-low voltage operation of 1 V,a large field-effect mobility of 18.9 cm2/Vs,a small subthreshold swing of 85 m V/decade and a high current on/off ratio of 107. Furthermore,the EDL TFT could work in dual coplanar gate mode. AND logic operation is realized. Our results demonstrate that such TFTs gated by P-doped nanogranular SiO2 films have potential applications in low-power flexible electronics.展开更多
基金The National Natural Science Foundation of China (No 50471014)The Science and Technology Foundation of Shanghai (No0210nm017)
文摘A theoretical model on the solvus line prediction of a film was proposed and applied to a nanogranular Al-Cu system. The calculation results show that the solvus line of solute Cu will markedly lower with the decrease of grain size, namely, the starting temperature of θ(Al_2Cu) precipitation in a nanogranular Al-Cu film will markedly lower than that of conventional coarse grain alloy with the same Cu concentration, and the precipitation temperatures calculated are comparable with the experimental ones. The theoretical model can be simply used to calculate the starting temperature of precipitation in Al-Cu films under three states: ① films with substrate; ② films without substrate; ③ ultrafine grain bulk alloy. As a result, the model is universal, moreover, can be, in principle, used to predict precipitation temperature in other systems.
文摘New magnetic air-stable nanogranular Fe thin films of 10 ± 1.2 nm thickness were prepared onto silicon wafers at 150℃ under inert atmosphere by controlled Chemical Vapor Deposition (CVD) of triiron dodecacarbonyl (Fe3(CO)12). These thin films, composed of sintered elemental Fe nanoparticles of 4.1 ± 0.7 nm diameter, are protected from air oxidation by a very thin carbon layer. The saturation magnetization of these thin Fe coatings was found to be close to that of bulk iron. The electrical resistivity behavior of the ferromagnetic thin films is similar to that of a semiconductor. In the present manuscript, these Fe thin coatings on Si wafers have been used as a catalyst for synthesizing crystalline carbon nanotubes (CNTs), by CVD using ethylene as a carbon precursor.
基金supported by the National Natural Science Foundation of China (Grant No.51302276)the Zhejiang Provincial Natural Science Foundation of China (Grant No.LY14A040009)in part by the Foundation of the Science and Technology Bureau of Wuhan City (Grant No.2014010101010006)
文摘Phosphorus doped（P-doped） nanogranular SiO2 films have been deposited by plasma-enhanced chemical vapor deposition. A high proton conductivity of;.2x10-4S/cm and a large electric double layer（EDL） capacitance of;.2μF/cm2 have been obtained. Flexible coplanar-gate EDL thin film transistors（TFTs） gated by P-doped nanogranular SiO2 films are self-assembled on plastic substrates at room temperature. Due to the big EDL capacitance,such TFTs show ultra-low voltage operation of 1 V,a large field-effect mobility of 18.9 cm2/Vs,a small subthreshold swing of 85 m V/decade and a high current on/off ratio of 107. Furthermore,the EDL TFT could work in dual coplanar gate mode. AND logic operation is realized. Our results demonstrate that such TFTs gated by P-doped nanogranular SiO2 films have potential applications in low-power flexible electronics.
