The densification and the fractal dimensions of carbon-nickel films annealed at different temperatures 300, 500, 800, and 1000℃ with emphasis on porosity evaluation are investigated. For this purpose, the refractive...The densification and the fractal dimensions of carbon-nickel films annealed at different temperatures 300, 500, 800, and 1000℃ with emphasis on porosity evaluation are investigated. For this purpose, the refractive index of films is determined from transmittance spectra. Three different regimes are identified, T 〈 500℃, 500℃ 〈 T 〈 800℃ and T 〉 800℃. The Rutherford baekscattering spectra show that with increasing the annealing temperature, the concentration of nickel atoms into films decreases. It is shown that the effect of annealing temperatures for increasing films densification at T 〈 500℃ and T 〉 800℃ is greater than the effect of nickel concentrations. It is observed that the effect of decreasing nickel atoms into films at 500℃ 〈 T 〈 800℃ strongly causes improving porosity and decreasing densification. The fractal dimensions of carbon-nickel films annealed from 300 to 500℃ are increased, while from 500 to 1000℃ these characteristics are decreased. It can be seen that at 800℃, films have maximum values of porosity and roughness.展开更多
Electrical conductivity of carbon-nickel composite films annealed at temperatures 300, 500 and 800℃ is studied over a temperature range of 50 300 K. While the conductivity data above room temperature show extended st...Electrical conductivity of carbon-nickel composite films annealed at temperatures 300, 500 and 800℃ is studied over a temperature range of 50 300 K. While the conductivity data above room temperature show extended state conduction, lowering the temperature from 150 to 50 K leads to the Berthelot-tvpe conduction mechanism. It can be seen that the films annealed at 500℃ have the maximum conductivity. The extent of the carrier wave function at 500℃ has the minima 2.87 × 10-7 cm and 2.45 ×10-7 cm in octahedral-metal stretching vibrations and intrinsic stretching vibrations of the metal at the tetrahedral site, respectivel. The average distances between two vibration octahedral and tetrahedral sites at 500℃ also have the minima 1.13 × 10-7 cm and 0.97×10 7 cm, respectivel3： The Berthelot temperature for fihns annealed at 800℃ ha^s the minimum of 9-1.3 K.展开更多
文摘The densification and the fractal dimensions of carbon-nickel films annealed at different temperatures 300, 500, 800, and 1000℃ with emphasis on porosity evaluation are investigated. For this purpose, the refractive index of films is determined from transmittance spectra. Three different regimes are identified, T 〈 500℃, 500℃ 〈 T 〈 800℃ and T 〉 800℃. The Rutherford baekscattering spectra show that with increasing the annealing temperature, the concentration of nickel atoms into films decreases. It is shown that the effect of annealing temperatures for increasing films densification at T 〈 500℃ and T 〉 800℃ is greater than the effect of nickel concentrations. It is observed that the effect of decreasing nickel atoms into films at 500℃ 〈 T 〈 800℃ strongly causes improving porosity and decreasing densification. The fractal dimensions of carbon-nickel films annealed from 300 to 500℃ are increased, while from 500 to 1000℃ these characteristics are decreased. It can be seen that at 800℃, films have maximum values of porosity and roughness.
文摘Electrical conductivity of carbon-nickel composite films annealed at temperatures 300, 500 and 800℃ is studied over a temperature range of 50 300 K. While the conductivity data above room temperature show extended state conduction, lowering the temperature from 150 to 50 K leads to the Berthelot-tvpe conduction mechanism. It can be seen that the films annealed at 500℃ have the maximum conductivity. The extent of the carrier wave function at 500℃ has the minima 2.87 × 10-7 cm and 2.45 ×10-7 cm in octahedral-metal stretching vibrations and intrinsic stretching vibrations of the metal at the tetrahedral site, respectivel. The average distances between two vibration octahedral and tetrahedral sites at 500℃ also have the minima 1.13 × 10-7 cm and 0.97×10 7 cm, respectivel3： The Berthelot temperature for fihns annealed at 800℃ ha^s the minimum of 9-1.3 K.
