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The cost reduction of hydrogen stations is a must in order to spread fuel cell vehicles. Generally, the PSA device in the hydrogen station occupies 30% of the construction cost. We have already proposed the cost reduction by replacing the PSA and CO shift converter with a membrane reactor to which CO2 selective facilitated transport membrane is built in 2011. Although the CO2 facilitated transport membrane achieved the CO2/H2 selectivity of 100 or more even if the operation temperature was 160°C, the durability was poor. Therefore, it is necessary to improve the heat resistance and the rate of reaction between carrier and CO2 furthermore so that it can be adopted for the membrane reactor. In order to improve the membrane performance at 160°C by keeping high water content of membrane, graphite rubbish was added to the membrane as it was expected to function as grain for water absorption. As a result, the CO2 selectivity of the membrane improved more than that of the previous membrane by 3 times.

Hydrogen of hydrogen station for FCV is usually produced by the reforming reaction, followed by the water gas shift reaction. The reformed gas contains a large amount of CO2, and this decreases the power efficiency although it does not influence the PEFC performance. The CO2 removal technology from the reformed gas is an important factor to improve the FCV performance. We developed a membrane for selective CO2 separation containing carbonate salt as a CO2 carrier. The support material of the CO2 carrier for a selective CO2 separation membrane should have water solubility, mechanical strength and heat resistance. We evaluated three support materials, PVA, AQN and NDP. The PVA membrane was broken at high temperature region though it showed good CO2 permeance at low temperature region. The AQN membrane had low CO2 permeance in all temperature regions. Although the NDP membrane had CO2 permeance at high temperature region, it should be improved further to increase the CO2 permeance.

Component effects such as a cocation and the zeolite support structure and the preparation condition effect of metal-loaded zeolites for the catalytic activity of direct NOx decomposition were examined using an experimental method. Regarding the cocation effect, the theoretical calculations were performed using a density functional method. The experimental results indicated that ZSM-5 was the best support of all of the zeolite tested such as ZSM-5, ZSM-11, SAPO-5, Y, and MOR. It was also experimentally found that the addition of a cocation such as Ca or Ni to Cu ion-exchanged ZSM-5 zeolite (Cu/ZSM-5) could prevent the catalyst from deactivation caused by O2 or H2O in the reaction gas. Regarding the cocation effect of Ca or Ni on Cu/ZSM-5, the theoretical calculations showed that the addition of these cocations increased the catalytic activity by promoting the desorption of oxygen yielded from NO decomposition and maintained NO adsorption on the catalyst under the coexistence of H2O. These results of the calculations supported the experimental results.

The states of cobalt loaded on Beta zeolite and their roles in selective catalytic reduction of nitrogen oxide (NO x ) by propane were studied. Raman spectroscopy clearly indicated that Co 3 O 4 was formed on highly loaded samples. Spectroscopic characterization combined with catalytic activity tests showed that highly dispersed cobalt is essential for NO x reduction. Co 3 O 4 promotes NO x reduction at low temperatures, but decreases the selectivity to NO x reduction especially at high temperatures through promotion of propane oxidation by oxygen. At ca. 100% loading, a broad band which cannot be assigned to zeolite framework nor Co 3 O 4 was observed at around 600 cm −1 . The intensity of this band showed a strong dependency on SiO 2 /Al 2 O 3 ratio, and we suggest it is related to Co–O–Co species. This cobalt species was suggested to have high activity towards NO x reduction.

The CuO/ZnO heterocontacts for carbon monoxide (CO) gas sensors were made using CuO ceramics with different histories, and their gas sensing characteristics were evaluated. The CuO/ZnO heterocontact made by the quenched CuO sintered compact showed enhanced CO and CO{sub 2} gas sensitivity, while that made by slowly cooled CuO showed no selective CO gas-sensing characteristics with no CO{sub 2} gas sensitivity. The quenched CuO ceramics were thermodynamically stable but the slowly cooled ones were not; therefore the adsorbed CO molecules on the quenched CuO are thought to be stable and have longer lifetimes. The specific reaction between the adsorbed CO on CuO and adsorbed oxygen on ZnO would be promoted by long lifetime adsorbed CO on CuO and that may be the origin of the enhanced CO gas sensitivity of the quenched-CuO/ZnO heterocontact. The concentrations of cation vacancies of the quenched CuO ceramics can be controlled by controlling the firing temperatures. However, when the CuO ceramics for the CuO/ZnO heterocontact were made by firing and quenching, the ability to be selective in CO gas sensing of the heterocontact was not easily controlled by the control of the defect concentrations of the CuO ceramics.

Selective catalytic reduction of NOx by propane was investigated on Co-Beta to clarify the loaded states of cobalt and their role in catalytic activity. At low ion exchange levels less than 100%, loaded cobalt is highly dispersed, which has a high selectivity for NOx reduction. At ion exchange levels much higher than 100%, Co3O4 appears as identified by Raman spectroscopy, and it contributes to propane oxidation by oxygen and lowers the selectivity especially at high temperatures.

Titanium nitride (TiN) and titanium (Ti) were deposited using a low-pressure and high-density helicon plasma process with titanium tetrachloride (TiCl4). This study aimed to clarify the characteristics of the TiN and Ti deposition processes and the properties of films. The rate-determining process of the TiN film-deposition reaction was changed with the TiCl4 partial pressure. High-deposition rate and excellent bottom coverage was achieved by using high TiCl4 partial pressure, but low film resistivity was not achieved simultaneously. By increasing the RF biased power, an improvement of the bottom coverage and the film resistivity was possible. The Ti film was deposited successfully by helicon plasma with a deposition rate of 4 nm min−1 and a film resistivity of 300 μΩ cm. It was found that synthesizing Ti films by plasma-enhanced chemical vapor deposition (CVD) required higher plasma density. The use of helicon plasma is promising for the deposition of TiN and Ti films. However, the deposited Ti film was an amorphous structure; this would be caused by impurities in this film (30 at% oxygen and 15 at% silicon). These impurities would be suspected to be induced by sputter etching of the quartz glass belljar used for the plasma generation chamber and by desorbing of H2O on the chamber wall.

From multiple regression analysis in the bottom coverage and resistivity of TiN films deposited using tetrakis(diethylamino)titanium (TDEAT), contour maps were calculated as functions of wafer temperature and reactor pressure. High bottom coverage and low resistivity were predicted at low pressure and low temperature with NH3 additives. Films have been deposited below 400°C and total reactor pressures below 133.3 Pa. Especially by adding a little NH3 to TDEAT, bottom coverages of 100% have been accomplished in 4.0 aspect ratio contacts with 300 nm diameter. Film resistivities have been also decreased from 24, 000 μΩ cm to about 10, 000 μΩ cm with 15 sccm NH3.

Basic process characteristics for Cu film deposition to be used in advanced ULSI interconnects have been studied by thermal LPCVD with liquid precursor Cu(hfac)(tmvs) (hexafluoro-acetylacetonate trimethyl-vinylsilane copper). For sufficient productivity in practical use, efforts were concentrated into obtaining high deposition rate with high film qualities of specific resistivity, surface flatness and adhesion. Three process chambers for preheating, TiN-PVD, and Cu-CVD functions were mounted on an ANELVA I-1060 single wafer cluster tool machine, where 6 inch wafers could be processed. Relationships between the deposition rate, specific resistivity, and Cu-CVD process parameters were analyzed using RSM (response surface methodology). Deposition rate over 100 nm/min was obtained at wafer temperature of 200°C, precursor flow rate of 0.67 g/min, carrier N2 flow rate of 400 sccm, and purge Ar flow rate of 125 sccm with specific resistivity of about 1.8 μΩ cm on TiN underlayer. This shows a promising process for future Cu interconnect technology.

The silicon semiconductor is widely used in various electronic equipments, and the graphite is an indispensable material used in manufacturing process of the silicon semiconductor.

It is known that the reflectivity of aluminum (Al) film deposited by chemical vapor deposition (CVD) decreases with an increase of film thickness as its surface roughens. A thin, smooth film is effective for filling small holes and narrow trenches by confonmal deposition, but a rough surface is not effective. In this study, a real-time monitoring of the CVD-A1 film deposition process has been attempted by measuring the reflected light intensity at the depositing film surface. By finishing the deposition when the monitored reflected light intensity of the He-Ne laser reached the maximum, a film with a very smooth surface could be reproduced. Furthermore, the lower limitation of smooth continuous film thickness was compared for four different cases. Investigated underlayers were Ti and TiN deposited by sputtering (SPT). On these underlayers, CVD-Al film was deposited without exposure to atmosphere or with exposure to atmosphere prior to the deposition, resulting in a total of four deposition conditions. The results showed that Al film deposited on TiN without exposure to atmosphere had the thinnest and the smoothest continuous film among the four. Since the thickness was 60 nm, the filling of 0.12-μm diameter holes or 0.12-μm wide trenches can be expected by this process.

The adsorption properties of oxygen and methane on Ga-ZSM-5 and Cu-ZSM-5 catalysts were examined by a TPD method to clarify the extraordinary selectivity of HC-SCR using methane on Ga-ZSM-5. It was observed that Ga-ZSM-5 did not adsorb oxygen but adsorbed methane dissociatively, while on Cu-ZSM-5 oxygen was dissociatively adsorbed and reacted with adsorbed ethylene.

Recording magnetic‐field sensitivity and readout stability for Tb/FeCo multilayer magneto‐optical (MO) disks, made by sputtering with Kr and Ar gas, were studied. The 100 Oe recording magnetic‐field sensitivity for Kr disks was obtained. The readout stability for Kr disk is superior to that for Ar disk. It seems that high readout stability for Kr disks is caused by the large wall coercivity and the large ratio of wall coercivity to nucleation coercivity.

Sensitive and selective carbon monoxide (CO) gas detection by a simple device is one of the most important research topics for safe environmental control. The gas sensing characteristics of CuO/ZnO heterocontacts are investigated. CuO/ZnO heterocontact, with Na[sub 2]CO[sub 3] added, showed selective CO gas sensing properties, while pure CuO/ZnO heterocontact showed higher sensitivity to H[sub 2] than to CO. It is suggested that the presence of a second phase containing Na[sup +] in CuO ceramic is essential for selective CO gas sensing by a heterocontact.

The effect of electron beam broadening on spatial resolution of EDS analysis in a 200 kV cold-FEG-TEM has been investigated for Type 316L stainless steel. Platinum (Pt) was evaporated on half the 316L TEM foil surface, and the difference in Pt concentration profiles obtained by the EDS method from the Pt evaporated surface and its opposite side was analysed as a function of foil thickness. Advantages of Pt use are that Pt is not included in the 316L steel, and it is easily formed as a stable and continuous thin evaporated film on the stainless steel. No change of spatial resolution caused by electron beam broadening was observed in stainless steel foils of less than about 140 nm thick subjected to EDS analysis with the FEG-TEM (incident probe size 1.6 +/- 0.2 nm diameter). Specimens of about 160 nm and more thick had a decrease in spatial resolution, but the decrease was smaller than that predicted from theoretical calculations of beam broadening for stainless steels. It is suggested that only the central part of the broadened electron beam with high intensity influences the spatial resolution of EDS analysis with the FEG-TEM.

The magnetic properties of Tb/FeCoTi multilayered films, prepared by two-source DC magnetron sputtering, have been investigated as a function of the layer thickness to improve the recording sensitivity of magnetooptical disks. For a fixed bilayer thickness ratio, the Curie temperature, T/sub c/, was strongly dependent on the Tb layer thickness and reached a maximum near 4 AA. The Kerr rotation theta /sub k/ is almost constant, independent of the Tb layer thickness. The effective composition shifts to the transition-metal-rich side with increase in Tb layer thickness, greater than 4 AA, made possible a pronounced reduction in T/sub c/ and effective composition adjustment, without decreasing theta /sub k/. Studies on recording characteristics revealed that recording sensitivity and bias magnetic fields are controlled by the Tb layer thickness, without sacrificing carrier-to-noise ratio. >

The durability of Cu-ZSM5 as a catalyst of selective reduction of NOx by hydrocarbons from the exhaust of stationary natural gas engines was examined. Even 100% ion-exchanged Cu-ZSM5 also showed a deterioration tendency at 773 K under wet conditions simulating lean-burning gas engine exhaust. From the results of the durability test of SOx concentration dependence, SOx was not considered to be the cause of the deterioration. The deteriorated Cu-ZSM5 was characterized by the measurements of BET surface area, CO adsorption, XRD, NMR, EXAFS, XANES as well as carbon analysis. Neither dealumination, carbon deposition nor loss of micropore was observed in the deteriorated sample, and CuO cluster formation and resultant loss of surface area of copper were clearly shown, therefore, the CuO cluster formation is considered to lead to deterioration of the activity of Cu-ZSM5.

Overwrite characteristics have been studied for Ge-Sb-Te phase change media under high linear velocity conditions, ranging from 11.3 m/s to 22.6 m/s, with mark-edge-recording (MER). The Ge 1 Sb 4 Te 7 recording layer composition was chosen for the rapid cooling structure to obtain a sufficient erase ratio under high linear velocity conditions. The optical optimization for the disk structure and the narrow-grooved substrate have been applied to improve erase characteristics with MER. The optical phase-difference-reproduction (PDR) has been studied to realize a high carrier to noise ratio (C/N). The pulse-width-reduction (PWR) recording compensation has been developed for high recording density. A 44.8 dB C/N was obtained for 0.68 micrometers minimum recording mark length. A -26.8 dB erase ratio was obtained at 22.6 m/s linear velocity.

The deposition of carbon on naphtha steam reforming catalysts depends on the chemical composition of the hydrocarbon oil, the steam/carbon ratio in the feedstock, as well as the process temperature and pressure. It is also affected by the presence of sulfur poisons. We have found that sulfur chemisorption on active Ru and Ni metal surfaces above half-saturation coverage at moderate temperatures stimulates the continuous deposition of relatively unreactive carbon which can eventually foul the catalyst.

A new volatile liquid copper precursor of allyloxytrimethylsilyl hexafluoroacetylacetonate copper (I) [Cu(hfac)(aotms)], termed Cypron was studied for the chemical vapor deposition of copper (Cu-CVD) thin films. This precursor has higher vapor pressure and more suitable thermal stability than the previously known trimethylvinylsilyl hexafluoroacetylacetonate copper (I) [Cu(hfac)(tmvs)]. In the presence of water vapor, smooth copper films were obtained with a high deposition rate of about 90 nm/min at a low temperature of 190°C. The resistivity of the films was as low as 1.9µΩ·cm. The step coverage and filling property of this novel precursor were excellent.

For in situ cleaning of inner reactor walls of copper chemical vapor deposition chambers used in the copper wiring process of LSI, etching of the deposited metallic copper is carried out by three step processes of copper oxidation, complexation with β-diketone, and vaporization to allow evacuator. In this paper, reactions suitable for the latter two processes are described. Reactions of copper oxide with three kinds of β-diketone, hexafluoroacetylacetone (Hhfac), acetylacetone and dipivaloylmethane, were studied using thermogravimetry in the range from room temperature to 400°C. Only Hhfac reacted with copper oxide showing etching in the temperature range above 170°C. At 350°C the weight ratio etching rate was 0.29 wt%/min at atmospheric pressure and 0.06 wt%/min at 665 Pa. The evaporation rate of the reaction product, Cu(hfac)2, was 5.3 wt%/min at 150°C, which is sufficiently higher than the etching rate of copper oxide. Reactions are as follows: 2CuO→Cu2O+1/2O2, Cu2O+Hhfac→Cu(hfac)+CuOH, 2Cu(hfac)→Cu(hfac)2+Cu, and Cu+CuO→Cu2O.

Antiferromagnetic nuclear magnetic resonance (AFNMR) of the Cu(2) site and the Cu-NQR of the Cu(1) site are investigated as a function of excess oxygen, y, in Pb 2 Sr 2 ( Y 1− x Ca x ) Cu 3 O 8+ y . We confirm the re-appearance of the antiferromagnetic order of the Cu(2) moments and the change of the valence of the Cu(1) site with hole-doping introduced by extra oxygen in the superconducting Pb 2 Sr 2 ( Y 0.5 Ca 0.5 ) Cu 3 O 8+ y .

To obtain a low-resistivity material and good gap-filling characteristics in the interconnect metallization process for advanced ULSI devices, we investigated the deposition rate and gap-filling characteristics of Cu chemical vapor deposition. We used trimethylvinylsilyl hexafluoro-acetylacetonate copper (I) as the source at deposition temperatures from 150 to 240°C and source partial pressures (P s) from 16 to 270 Pa. The deposition rate was studied as functions of the deposition temperature and P s. The deposition rate increased as the temperature increased, but gap filling simultaneously deteriorated under constant P s. To obtain good gap filling, P s should be increased, but P s is restricted by the saturated vapor pressure. Interpretations are given for gap-filling characteristics from the viewpoint of the deposition mechanism. It is concluded that the maximum deposition rate with excellent gap filling is regulated by the source vapor pressure. We succeeded in satisfactorily filling a hole of an aspect ratio of 5.5 at 200 Pa of P s and at 170°C with the deposition rate of 40 nm/min. To obtain the same hole filling characteristic at a deposition temperature of 180°C, P s should be raised to 250 Pa and the deposition rate should be 60 nm/min.

Determination par spectrometrie des constantes de fixation et de dissociation de l'oxygene avec le [meso tetrakis(o-pivalamidophenyl) porphinate] cobalt(II) complexe par differents ligands (methyl- et dimethylimidazole, amino-4 pyridine,…) et disperse dans une matrice de PBMA. Determination du coefficient de diffusion de l'oxygene dissous d'apres la loi de Henry et de l'oxygene coordonne au complexe d'apres l'isotherme de Langmuir

Spectroscopic Study of Oxygen Sorption and Diffusion in a Membrane Containing a Cobalt Porphyrin Complex

Anisotropy changes caused by He+ and H 2 + implantations in (100), (110), and (111) magnetic garnet films have been studied. In (100) films, in striking contrast to (111) films, uniaxial anisotropy field changes were almost the same for He+ and H 2 + implantations. In (110) films, the orthorhombic anisotropy parameter B changed greatly with H 2 + implantations, consistent with anisotropy changes in (111) films. The change in parameter A for He+-implanted (110) films was of the same order as for H 2 + implantations. Magnetocrystalline anisotropy K 1 in H 2 + implanted films was determined from the angular dependence of (100) in-plane resonance fields. The sign of K 1 changed to positive with H 2 + implantation. It was found that H 2 + implantations have a great effect on ? 111 and K 1 , but have little influence on ? 100 .

Preparation de la membrane en dispersant dans du polymethacrylate de butyle le complexe [α, α', α″, α''' μeso-tetrakis (o-pivalamidophenyl) porphinato] cobalt II-methyl-1 imidazole, le transfert d'oxygene est ainsi ameliore

The effect of sulfur poisoning on low temperature steam reforming reaction using a Ru/Al2O3 catalyst was investigated using nhexane containing a low concentration of sulfur as the raw material.In addition, catalysts having different contents of sulfur were prepared by H2S adsorption. Using them, carbon deposition during low temperature steam reforming of naphtha was examined.The behavior of carbon deposition was then compared to a case without sulfur poisoning.As a result, it was found that sulfur poisoning not only seriously reduces the activity of catalysts, but also promotes carbon deposition. Without sulfur poisoning, carbon accumulation on catalysts does not occur during low temperature steam reforming of naphtha.

Precise magnetization measurements and neutron diffraction measurements are carried out for Mg 1- p Mn p Te 2 near the critical concentration p = 0.5 for the antiferromagnetic ordering. A magnetization property which is similar to micto-magnetism is observed for p = 0.35 and p = 0.45 samples. The susceptibility shows an anomaly at T f and field-cooling effect is notable below T f . Neutron diffraction experiments show that most of the manganese moments are ordered antiferromagnetically for p = 0.53 while small fractions of Mn 2+ are ordered for p = 0.45 and p = 0.35.

Kinetic studies of methane in a microreactor were carried out to clarify the reaction mechanism of a diffusive catalytic combustion burner for city gas using a combustion catalyst composed of porous alumina fibers impregnated with rhodium. Fresh catalysts, H2S treated catalysts and life test catalysts were all tested in oxidation, steam reforming and cracking reactions under conditions similar to those of the burner. The results show that there are two kinds of oxidation mechanisms: one is complete oxidation under high oxygen pressure in which oxygen is dissociatively adsorbed over rhodium, the other is partial oxidation under a lower oxygen pressure in which highly active oxygen interacts with rhodium to produce CO and H2. The partial oxidation is assumed to be the predominant methane reaction within the burner because of its high rate. Since any steam reforming reaction was perfectly poisoned by sulfur and a carbon-producing cracking reaction was not observed, these two reactions are assumed to be unimportant in the burner.

Une solution toluenique de polymethacrylate de butyle et de CoPIm ({α,α',α'',α'''-meso-tetrabis [o-pivalamidophenyl] porphinato} cobalt-methyl-1 imidazole), est coulee sur une plaque de Teflon puis sechee

A systematic study of magnetooptical properties for four different varieties of the (Pr,Nd)-(Tb,Dy)-FeCo system, focusing on temperature and wavelength dependences of Kerr rotation theta /sub k/ for alloy films and multilayered films, was made. The same relation between Curie temperature T/sub c/ and theta /sub k/ at a 830-nm wavelength was obtained for (Pr,Nd)-(Tb,Dy)-FeCo and (Tb,Dy,GdTb)-FeCo alloy films where the Co to FeCo ratio was less than 20 at.%. It was found that in the range of 500 nm to 900 nm the absolute magnitude of theta /sub k/ for all quaternary systems was always less than that for Dy-FeCo. These results suggest that amorphous rare-earth-FeCo alloy films containing Nd or Pr are not superior to (Tb,Dy)-FeCo films in regard to recording sensitivity and recording density in magnetooptical disks. On the other hand, theta /sub k/ enhancement was observed for Nd-Dy-FeCo multilayered films. This theta /sub k/ enhancement is not caused by the addition of Nd, but is due to the effect of film microstructure on theta /sub k/. >

Magnetization measurements using a vibrating-sample-magnetometer for helium and hydrogen implanted garnet films were carried out up to the Curie temperature. Using these data, the uniaxial anisotropy was also deduced by FMR. The magnetization and absolute value of the uniaxial anisotropy for helium-implanted films decrease more markedly at high temperatures, compared with the values for hydrogen-implanted films. It is shown from the normalized magnetization values that the defects created by hydrogen implantations might be smaller than those created by helium implantations. The differences in the bubble operation limits at high temperatures between helium and hydrogen implantations can be attributed to these different magnetic properties for helium- and hydrogen-implanted films.