• Progress in Superconductivity and Cryogenics
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• v.8 no.1
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• pp.23-25
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• 2006

Optimization of process variables, including oxygen and water partial pressure and also an nesting temperature, was performed in batch-type process to fabricate YBCO films on LaAlO3 single crystal. In this work, YBCO oxide powder was used as a starting precursor for metal-organic deposition(MOD)method. The precursor films were fabricated in batch furnace and they were converted to the epitaxial YBCO films at the same furnace with varying the process variables. The oxygen partial pressure was varied from 100ppm to 2000ppm and the water partial pressure from 1.2% to 12.2%. The window for optimal P(O2) was narrow about 700ppm for batch-type process. YBCO films in bathc-thype MOD process were optimized at 740-770oC and P(H2O) of 2.3%-7.3%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.451-454
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• 2001

The ionic conductivity of cubic solid solutions in the system $Y_{2}O_{3}-ZrO_{2}$ prepared by SHS was examined. Conductivity-temperature data obtained at $1000^{\circ}C$ in atmosphere of low oxygen partial pressure ($10^{-40}$ atm) for $Y_{2}O_{3}-ZrO_{2}$ cubic solid solutions indicated that these materials could be reduced, the degree of reduction being related to the measuring electric field. At low impressed fields no reduction was observed. Thus, these conductivity data give a transference number for the oxygen ion in $Y_{2}O_{3}-ZrO_{2}$ cubic solid solutions greater than 0.99.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.451-454
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• 2001

The ionic conductivity of cubic solid solutions in the system Y$_2$O$_3$-ZrO$_2$ prepared by SHS was examined. Conductivity-temperature data obtained at 1000$^{\circ}C$ in atmosphere of low oxygen partial pressure (10$\^$-40/ atm) for Y$_2$O$_3$-ZrO$_2$ cubic solid solutions indicated that these materials could be reduced, the degree of reduction being related to the measuring electric field. At low impressed fields no reduction was observed. Thus, these conductivity data give a transference number for the oxygen ion in Y$_2$O$_3$-ZrO$_2$ cubic solid solutions greater than 0.99.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.31-36
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• 2000

180g of fermented soy paste and 150g of red pepper paste were packaged in glass jars of 232 mL with different conditions of active packaging and then stored at $13^{\circ}C$ for about 170 and 128 days, respectively. During the storage, package atmosphere, surface color, pH, acidity and microbial flora were monitored to see the effect of packaging conditions. Test packaging conditions include package equipped with $Ca(OH)_2\;as\;CO_2$ absorber, package with pinhole and closed control one. Closed control packages of soypaste and red pepper paste showed the increased $CO_2$ partial pressure, the decreased $O_2$ partial pressure and the constant $N_2$ partial pressure to produce high pressure buildup with storage. The paste packages with $Ca(OH)_2$ maintained relatively low $CO_2$ partial pressure and thus the package pressure close to normal atmospheric pressure for initial storage period of 70 days. The packages with air pinhole channel had the partial pressures of $O_2\;and\;N_2$ decreased with storage time, while $CO_2$ partial pressure first increased to a maximum and then slowly decreased thereafter Without any pressure increase the packages with pinhole gave the lowest quality changes possibly due to the effect of package atmosphere, but it had problem of mold contamination and growth for soy paste after 120 days. There were no difference in microbial flora between the packages after about 70 day storage.

• Journal of the Korean Vacuum Society
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• v.8 no.3B
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• pp.333-339
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• 1999

$RuO_2$ thin films were prepared with various deposition conditions by rf magnetron sputtering. The films were annealed in vacuum, air, and air-vacuum, after that, the structural and electrical properties of the films were investigated. As the substrate temperature increases, the preferred orientation of the films changes from (101) to (200), and the grain size increases; especially, at $500^{\circ}C$, the size considerably increases. The preferred orientation of the films changes from (200) to (101) and the roughness of surface increase with the increase in oxygen partial pressure. The lowest value of resistivity of $RuO_2$ we prepared is $1.5\times 10^{-5}\Omega\codt\textrm{cm}$ at the conditions of $400^{\circ}C$ and 10% of oxygen partial pressure. After the processes of annealing, the films deposited at $400^{\circ}C$ and a oxygen partial pressure of 10% were relatively stable. The films deposited at $500^{\circ}C$ have denser structure and smoother surface when the films are annealed in vacuum after annealing in air.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.326-328
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• 1999

We investigated the effects of residual gas partial pressure on the property of a CeO$_2$ buffer layer on a textured Ni tape, where the buffer layer was deposited by e-beam evaporation. The oxygen partial pressure were varied from 10$^{-7}$ to 10$^{-4}$ Torr. we also changed the surface condition for the surface oxygenation. We'll describe the detail of the resultant textures of the buffer layers and effects of YBCO growth on them

• Journal of Surface Science and Engineering
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• v.45 no.5
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• pp.206-211
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• 2012

Process analysis was carried out during deposition of MgO by inductively coupled plasma assisted reactive magnetron sputtering in Ar and $O_2$ ambient. At the initiation of Mg sputtering with bipolar pulsed dc power in Ar ambient, total pressure showed sharp increase and then slow fall. To analyse partial pressure change, QMS was used in downstream region, where the total pressure was maintained as low as $10^{-5}$ Torr during plasma processing, good for ion source and quadrupole operation. At base pressure, the major impurity was $H_2O$ and the second major impurity was $CO/N_2$ about 10%. During sputtering of Mg in Ar, $H_2$ soared up to 10.7% of Ar and remained as the major impurity during all the later process time. When $O_2$ was mixed with Ar, the partial pressure of Ar decreased in proportion to $O_2$ flow rate and that of $H_2$ dropped down to 2%. It was understood as Mg target surface was oxidized to stop $H_2$ emission by Ar ion sputtering. With ICP turned on, the major impurity $H_2$ was converted into $H_2O$ consuming $O_2$ and C was also oxidized to evolve CO and $CO_2$.

• Journal of Powder Materials
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• v.31 no.2
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• pp.163-168
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• 2024

As the demand for lithium-ion batteries for electric vehicles is increasing, it is important to recover valuable metals from waste lithium-ion batteries. In this study, the effects of gas flow rate and hydrogen partial pressure on hydrogen reduction of NCM-based lithium-ion battery cathode materials were investigated. As the gas flow rate and hydrogen partial pressure increased, the weight loss rate increased significantly from the beginning of the reaction due to the reduction of NiO and CoO by hydrogen. At 700 ℃ and hydrogen partial pressure above 0.5 atm, Ni and Li₂O were produced by hydrogen reduction. From the reduction product and Li recovery rate, the hydrogen reduction of NCM-based cathode materials was significantly affected by hydrogen partial pressure. The Li compounds recovered from the solution after water leaching of the reduction products were LiOH, LiOH·H₂O, and Li₂CO₃, with about 0.02 wt% Al as an impurity.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.288-295
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• 1999

Partial conductivities contributed by electron holes, oxygen ions, and protons were caluclated in $SrZr_{0.95}Y_{0.05}O_{2.975}$, using the reported formulae derived from the defect chemistry of HTPCs. Required parameters were obtained from the graphical analysis of total conductivity variation against partial pressure of water vapor and oxygen. Predicted overall conductivities showed a reasonable agreement with experimental measurements. The conductivity of the material showed a linear increase with square root of the water vapor pressure. This increase was due to proton conduction in an almost pure ionic conductivity. The calculation of partial conductivities at $800^{\circ}C$ resulted in an almost pure ionic conductivity at $P_{02}=10^{-10}$ atm and a predominant hole conductivity at $P_{02}=10^{-10}$ atm. Pure proton conduction was not expected at this temperature, contrary to the earlier reports. Discussions were made in relation with reported thermodynamic data and defect structure of the material. It was shown that from the total conductivity dependence on water vapor pressure, the pure ionic conductivity at low oxygen partial pressures could be separated into protonic and oxygen ionic conductivity in $ZrO_2$-based HTPCs.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.88-89
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• 2007

ZnO thin films were deposited on $Al_2O_3$ (alumina) substrates by pulsed laser deposition (PLD) using Nd:YAG laser with a wavelength of 355nm, at room temperature and oxygen partial pressure of 1, 10, 30, 50, 100, and 200m Torr. Furthermore, deposited ZnO thin films were post-annealed at 400, 550, $600^{\circ}C$. The effects of oxygen partial pressure and post-annealing temperature on structural properties of the deposited films have been investigated by means of X-ray diffraction (XRD), and atomic force microscope (AFM), respectively. It has been found that ZnO thin films exhibit c-axis orientation, exhibiting an increased foil width at half maximum (FWHM) value of (002) diffraction peak at 30m Torr oxygen partial pressure and higher post-annealing temperature ($700^{\circ}C$).