Gd thin films with different thickness （about 10 nm and 0.5 nm） were deposited on Si（100） by laser molecular beam epitaxy （LMBE）. Thickness dependence of the initial oxidation behaviors of Gd films was studied b...Gd thin films with different thickness （about 10 nm and 0.5 nm） were deposited on Si（100） by laser molecular beam epitaxy （LMBE）. Thickness dependence of the initial oxidation behaviors of Gd films was studied based on the in situ X-ray photoelectron spectroscopy （XPS） and ultraviolet photoelectron spectroscopy （UPS） analysis under ultra-high vacuum （UHV） condition. When the thin film is around 10 urn, the XPS results show that Gd is extremely reactive with oxygen forming Gd oxides and the oxides of Gd are easily hygroscopic. The UPS results show that the Gd 4fhas a double-peak structure and the double-peak structure of Gd 4fevolves into a single-peak feature after exposing to air. When the thickness of the Gd film decreases to about 0.5 urn, the reactivity of Gd film with oxygen is decreased by the diffusion of Si component into Gd layers based on the XPS and UPS results. It is suggested that the silicon atoms segregate at the grain boundaries of Gd film to form a barrier, which block the further diffusion of oxygen and water vapor into the Gd layers.展开更多
Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force micr...Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force microscopy, X-ray diffractometer, transmission electron microscopy, and Fourier transform infrared spectroscopy and UV-vis spectroscopy. Surface morphology reveals the smooth surface of these films （RMS： from 0.503 to 2.849 nm）. The presence of obviously-broadened peaks for diffraction planes （111） suggests a presence of very tiny crystallites distributed along a preferred crystallographic orientation. Transmission electron microscopy investigations confirmed the formation of tiny crystallites due to the implantation of erbium ions. Due to the increase of nominal H concentration, the intensity of the broad absorbance from 190-260 nm increased.展开更多
基金Funded by the Key Laboratory of National Defense Science and Technology(No.9140c6806080c68)
文摘Gd thin films with different thickness （about 10 nm and 0.5 nm） were deposited on Si（100） by laser molecular beam epitaxy （LMBE）. Thickness dependence of the initial oxidation behaviors of Gd films was studied based on the in situ X-ray photoelectron spectroscopy （XPS） and ultraviolet photoelectron spectroscopy （UPS） analysis under ultra-high vacuum （UHV） condition. When the thin film is around 10 urn, the XPS results show that Gd is extremely reactive with oxygen forming Gd oxides and the oxides of Gd are easily hygroscopic. The UPS results show that the Gd 4fhas a double-peak structure and the double-peak structure of Gd 4fevolves into a single-peak feature after exposing to air. When the thickness of the Gd film decreases to about 0.5 urn, the reactivity of Gd film with oxygen is decreased by the diffusion of Si component into Gd layers based on the XPS and UPS results. It is suggested that the silicon atoms segregate at the grain boundaries of Gd film to form a barrier, which block the further diffusion of oxygen and water vapor into the Gd layers.
基金Funded by the Fund of the Science and Technology on Plasma Physics Laboratory(No.9140C680501110C6803)
文摘Erbium dihydride thin films were prepared by pulsed laser deposition on Si（100） substrates using erbium target under different low hydrogen pressures. The properties of these films were examined by atomic force microscopy, X-ray diffractometer, transmission electron microscopy, and Fourier transform infrared spectroscopy and UV-vis spectroscopy. Surface morphology reveals the smooth surface of these films （RMS： from 0.503 to 2.849 nm）. The presence of obviously-broadened peaks for diffraction planes （111） suggests a presence of very tiny crystallites distributed along a preferred crystallographic orientation. Transmission electron microscopy investigations confirmed the formation of tiny crystallites due to the implantation of erbium ions. Due to the increase of nominal H concentration, the intensity of the broad absorbance from 190-260 nm increased.
