Thin films of Bismuth Telluride (Bi<sub>2</sub>Te<sub>3</sub>) are prepared by thermal evaporation from nanopowders on the glass substrates. The XRD patterns of films show that all the films ar...Thin films of Bismuth Telluride (Bi<sub>2</sub>Te<sub>3</sub>) are prepared by thermal evaporation from nanopowders on the glass substrates. The XRD patterns of films show that all the films are polycrystalline and the crystalline increased by annealing temperature. Measuring of the thermoelectric power of thin films in the temperature range 300 to 380 K shows that Seebeck Coefficients have both negative and positive values, indicating that the films have both n-type and p-type conductivity. The re-crystallization of films is done by annealing from 130°C to 175°C and Seebeck Coefficient varied from -150 to 100 μV/K.展开更多
By FP-LAPW calculations, the structural, elastic, Debye and Curie temperatures, electronic and magnetic properties of Co2 VAl are investigated. The results indicate that Ferromagnetic （FM） phase is more stable than ...By FP-LAPW calculations, the structural, elastic, Debye and Curie temperatures, electronic and magnetic properties of Co2 VAl are investigated. The results indicate that Ferromagnetic （FM） phase is more stable than Anti- Ferromagnetic （AFM） and Non-magnetic （NM） ones. In addition, C11-C12 〉 0, C44 〉 0, and B 〉 0 so Co2 VAl is an elastically stable material with high Debye temperature. Also, the BIG ratio exhibits a ductility behavior. The relatively high Curie temperature provides it as a favorable material for spintronic application. It＇s electronic and magnetic properties are studied by GGA ＋U approach leading to a 100% spin polarization at Fermi level.展开更多
文摘Thin films of Bismuth Telluride (Bi<sub>2</sub>Te<sub>3</sub>) are prepared by thermal evaporation from nanopowders on the glass substrates. The XRD patterns of films show that all the films are polycrystalline and the crystalline increased by annealing temperature. Measuring of the thermoelectric power of thin films in the temperature range 300 to 380 K shows that Seebeck Coefficients have both negative and positive values, indicating that the films have both n-type and p-type conductivity. The re-crystallization of films is done by annealing from 130°C to 175°C and Seebeck Coefficient varied from -150 to 100 μV/K.
基金Supported by the simulation of Nano Physics Lab center of Kermanshah Branch,Islamic Azad University
文摘By FP-LAPW calculations, the structural, elastic, Debye and Curie temperatures, electronic and magnetic properties of Co2 VAl are investigated. The results indicate that Ferromagnetic （FM） phase is more stable than Anti- Ferromagnetic （AFM） and Non-magnetic （NM） ones. In addition, C11-C12 〉 0, C44 〉 0, and B 〉 0 so Co2 VAl is an elastically stable material with high Debye temperature. Also, the BIG ratio exhibits a ductility behavior. The relatively high Curie temperature provides it as a favorable material for spintronic application. It＇s electronic and magnetic properties are studied by GGA ＋U approach leading to a 100% spin polarization at Fermi level.
