Thin films of VO_(2)single-crystalline on(0001)sapphire substrates have been prepared by visible pulsed laser ablation technique.The crystal quality and properties of the films are evaluated through electrical resista...Thin films of VO_(2)single-crystalline on(0001)sapphire substrates have been prepared by visible pulsed laser ablation technique.The crystal quality and properties of the films are evaluated through electrical resistance measurement,x-ray diffraction(XRD),and Rutherford-backscattering spectroscopy/channeling(RBS/C)analysis.The dependence of the surface electrical resistance of the films on the temperature shows semiconductor-to-metal transitions with the resistance change of 7×10^(3)-2×10^(4).The hysteresis widths are from less than 1 to 3 K.XRD and RBS/C data reveal that the films prepared in particular conditions are single-crystalline VO_(2)with the(010)planes parallel to the surface of the sapphire substrate.展开更多
Diamond films(DF)were preliminarily B doped in situ during chemical vapor deposition.Subsequently,the films were implanted with 120keV H^(+)to dose of 5×10^(14)~5×10^(16)cm^(-2).After the implantation,the B ...Diamond films(DF)were preliminarily B doped in situ during chemical vapor deposition.Subsequently,the films were implanted with 120keV H^(+)to dose of 5×10^(14)~5×10^(16)cm^(-2).After the implantation,the B doped DF become insulating and Raman measurements indicate that the implantation has amorphous carbon and graphite etched.It is known that the formation of H-B pairs plays an important pole in property changes.However,for larger dose cases,the electrical resistance of DF is influenced by radiation damage and/or non-diamond phases.In addition to them,annealing makes the specimens conducting again.This phenomenon maybe has potential for application in designing DF device.展开更多
文摘Thin films of VO_(2)single-crystalline on(0001)sapphire substrates have been prepared by visible pulsed laser ablation technique.The crystal quality and properties of the films are evaluated through electrical resistance measurement,x-ray diffraction(XRD),and Rutherford-backscattering spectroscopy/channeling(RBS/C)analysis.The dependence of the surface electrical resistance of the films on the temperature shows semiconductor-to-metal transitions with the resistance change of 7×10^(3)-2×10^(4).The hysteresis widths are from less than 1 to 3 K.XRD and RBS/C data reveal that the films prepared in particular conditions are single-crystalline VO_(2)with the(010)planes parallel to the surface of the sapphire substrate.
基金Supported by the National Natural Science Foundation of China under Grant No.59582009.
文摘Diamond films(DF)were preliminarily B doped in situ during chemical vapor deposition.Subsequently,the films were implanted with 120keV H^(+)to dose of 5×10^(14)~5×10^(16)cm^(-2).After the implantation,the B doped DF become insulating and Raman measurements indicate that the implantation has amorphous carbon and graphite etched.It is known that the formation of H-B pairs plays an important pole in property changes.However,for larger dose cases,the electrical resistance of DF is influenced by radiation damage and/or non-diamond phases.In addition to them,annealing makes the specimens conducting again.This phenomenon maybe has potential for application in designing DF device.
