The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Hitoshi Sakamoto - One of the best experts on this subject based on the ideXlab platform.
-
Thermal Desorption of surface phosphorus on Si(100) surfaces
Surface Science, 1999Co-Authors: F. Hirose, Hitoshi SakamotoAbstract:Abstract Thermal Desorption of phosphorus on Si(100) surfaces has been investigated by varying the phosphorus coverage from zero to one monolayer (ML). The reaction path of phosphorus Desorption is complicated and strongly dependent upon the phosphorus coverage. In the thermal Desorption spectra, there are three apparent Desorption peaks at ∼750, ∼850 and ∼1000°C. The entire phosphorus atoms on the surface desorb as P 2 through recombinative reactions irrespective of the Desorption temperature and the coverage. In the lower coverages below 0.2 ML, the thermal Desorption spectra are characterized by a single peak at ∼900°C which is considered to be the Desorption from SiP heterodimers. At higher coverages exceeding 0.2 ML, it is considered that three Desorption schemes from PP, SiP dimers and defects coexist in the reaction stage.
-
Evaluation of surface hydrogen Desorption from Si H terminated Si(100) surfaces by thermal Desorption spectroscopy
Applied Surface Science, 1998Co-Authors: F. Hirose, Hitoshi SakamotoAbstract:Abstract An analysis method obtaining kinetic parameters of H2 Desorption from Si–H terminated Si(100) surfaces by using thermal Desorption spectroscopy (TDS) is presented. So far, the H2 partial pressure in the chamber has been assumed to be proportional to the Desorption rate in the thermal Desorption experiments. However, this assumption may possibly lead to errors in determining the hydrogen Desorption reaction order. To eliminate the error, we show a calculation method where the Desorption rate is directly derived from the H2-partial pressure in consideration with the residence time of H2. The H2 Desorption rate–substrate temperature spectrum obtained in this method allows a precise determination of the reaction order, the activation energy and the frequency factor for hydrogen Desorption.
F. Hirose - One of the best experts on this subject based on the ideXlab platform.
-
Thermal Desorption of surface phosphorus on Si(100) surfaces
Surface Science, 1999Co-Authors: F. Hirose, Hitoshi SakamotoAbstract:Abstract Thermal Desorption of phosphorus on Si(100) surfaces has been investigated by varying the phosphorus coverage from zero to one monolayer (ML). The reaction path of phosphorus Desorption is complicated and strongly dependent upon the phosphorus coverage. In the thermal Desorption spectra, there are three apparent Desorption peaks at ∼750, ∼850 and ∼1000°C. The entire phosphorus atoms on the surface desorb as P 2 through recombinative reactions irrespective of the Desorption temperature and the coverage. In the lower coverages below 0.2 ML, the thermal Desorption spectra are characterized by a single peak at ∼900°C which is considered to be the Desorption from SiP heterodimers. At higher coverages exceeding 0.2 ML, it is considered that three Desorption schemes from PP, SiP dimers and defects coexist in the reaction stage.
-
Evaluation of surface hydrogen Desorption from Si H terminated Si(100) surfaces by thermal Desorption spectroscopy
Applied Surface Science, 1998Co-Authors: F. Hirose, Hitoshi SakamotoAbstract:Abstract An analysis method obtaining kinetic parameters of H2 Desorption from Si–H terminated Si(100) surfaces by using thermal Desorption spectroscopy (TDS) is presented. So far, the H2 partial pressure in the chamber has been assumed to be proportional to the Desorption rate in the thermal Desorption experiments. However, this assumption may possibly lead to errors in determining the hydrogen Desorption reaction order. To eliminate the error, we show a calculation method where the Desorption rate is directly derived from the H2-partial pressure in consideration with the residence time of H2. The H2 Desorption rate–substrate temperature spectrum obtained in this method allows a precise determination of the reaction order, the activation energy and the frequency factor for hydrogen Desorption.
Nobutsune Takezawa - One of the best experts on this subject based on the ideXlab platform.
-
temperature programmed Desorption and infrared spectroscopic studies of nitrogen monoxide adsorbed on ion exchanged copper mordenite catalysts
Applied Catalysis A-general, 1998Co-Authors: Masahide Shimokawabe, Kenichiro Tadokoro, Shintaro Sasaki, Nobutsune TakezawaAbstract:Abstract The natures of the surface species formed upon adsorption of NO on copper-ion exchanged mordenite catalysts were investigated by means of temperature programmed Desorption (TPD) and diffuse reflectance infrared spectroscopy. When nitrogen monoxide (NO) was contacted with Cu/mordenite at room temperature, the evolution of dinitrogen monoxide (N 2 O) and nitrogen occurred, accompanied by the formation of the adsorbed oxygen species (Os). In the TPD runs, three NO Desorption peaks appeared, with maxima at 383 K (α-NO peak), 523 K (β-NO peak), and 673 K (γ-NO peak). The Desorptions of oxygen and nitrogen dioxide (NO 2 ) were observed together with the Desorption of NO at 673 K. These α-NO and β-NO peaks correspond to the Desorptions of nitrogen oxide species which adsorbed as NO-type species. The Desorptions of γ-NO, γ-NO 2 and γ-O 2 at 673 K arose from the decomposition of NO 3 -type adsorbed species. The NO 3 -type species may have formed by the reaction between NO and the adsorbed oxygen species (Os). By comparison of the rate of the NO decomposition with that of the decomposition of NO 3 -type adsorbed species, it was shown that the NO 3 -type adsorbed species plays a pivotal role in the decomposition of NO as intermediate of the reaction.
Alain Perrard - One of the best experts on this subject based on the ideXlab platform.
-
An intermittent temperature-programmed Desorption method for studying kinetics of Desorption from heterogeneous surfaces
Applied Surface Science, 2004Co-Authors: François Gaillard, M. Abdat, J.p. Joly, Alain PerrardAbstract:Abstract Reported results show the interest of an intermittent temperature-programmed Desorption (ITPD) technique for gaining information on thermodynamics and Desorption kinetics of small molecules from the surface of dispersed solids. This technique is a differential form of TPD where a saw-tooth heating program is used to generate a sequence of interrupted Desorptions. Two examples are described and discussed in terms of heat of Desorption, activation energy of Desorption and frequency factors. We first considered ammonia Desorption from two different zeolites, that is H-ZSM5 and H-Ω, in order to get information on their surface acidity. Secondly, oxygen Desorption from SnO 2 was investigated in order to get quantitative data on O 2 /SnO 2 interaction, this oxide being used in sensors of reducing gases in the atmosphere.
Toshiaki Yamamoto - One of the best experts on this subject based on the ideXlab platform.
-
Distinction between nonthermal plasma and thermal Desorptions for NOx and CO2
Applied Physics Letters, 2007Co-Authors: Keiichiro Yoshida, Masaaki Okubo, Toshiaki YamamotoAbstract:Nonthermal plasma (NTP) Desorption is used in NOx aftertreatment systems for diesel engine exhaust gas. The authors conducted Desorption experiments for both NTP and thermal Desorptions under similar conditions and electric power levels. The results confirm that NO, NO2, and CO2 are desorbed by the NTP at lower gas temperatures, while the total amount of desorbed gas is nearly the same for both the processes. Moreover, the amount of NO2 for the NTP Desorption is greater than that for the thermal Desorption. The Desorption of CO2 by the NTP is more significant and rapid than that by the thermal Desorption.
