• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.2
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• pp.94-103
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• 1991

ZnO-$P_2O_5$ system glasses containing 45 to 60 mol% ZnO have been melted at$1200^{\circ}C$and crystallized through controlled heat treatment. The properties of the base glass and crystallized glass were examined with XRD. FTIR. density. thermal expansion, electric conductivity, hardness. The principal crystalline phase was identified as zinc metaphosphate [$Zn(PO_3)_2$ in crystallized glasses containing 45-55mol% ZnO and zinc pyrophosphate ($Zn_2P_2O_7$) in the sample of 60mol% ZnO with X - ray diffraction analysis. Thermal expansion coefficient and DC electrical conductivity were varied with direction of oriented crystalline in the samples containing 50-60mol% ZnO. This suggests the existance of the oriented crystalline.

• Journal of the Korean Ceramic Society
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• v.34 no.8
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• pp.811-816
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• 1997

SiO2-P2O5-B2O3 glass soot was fabricated by flame hydrolysis deposition and their properties by SEM, XRD, TGA-DSC were investigated., The mechanism of consolidation process of a glass soot as a function of consolidation temperature was analyzed by SEM observations. In the XRD patterns, the crystalline peaks which seem to be generated from B2O3 and BPO4 were observed. When the temperature of heat treatment exceeded 105$0^{\circ}C$, the non-crystalline state of SiO2-P2O5-B2O3 glass was observed. In the TGA-DSC curves, the evaporation of water molecule by a sudden endothermic reaction was observed at 128$^{\circ}C$ and a broad endothermic peak was seen in the temperature range of 40$0^{\circ}C$-95$0^{\circ}C$, without any weight loss. Finally, this peak was began to recover its baseline at 953$^{\circ}C$. This point is equal to the temperature at which the densification begins. Furthermore, we observed that the addition of dopants such as P2O5 and B2O3 decrease the onset of consolidation temperature till 95$0^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.383-386
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• 1999

The importance of rechargeable lithium cells has been emphasized. So a large variety of materials has been discovered and evaluated for use as reversible cathodes and electroyltes. This paper examines the charge/discharge properties and the charge/discharge cycling life of Li$_2$O-P$_2$O-V$_2$O$_{5}$Li cells. In audition, DTA tests were carried out on Li$_2$O-P$_2$O-V$_2$O$_{5}$ glass. As a result the best performance was achieved when 0.3Li$_2$O-0.1P$_2$O$_{5}$-0.6V$_2$O$_{5}$Li cells was mixed with SP270. that is discharge capacity of 240mAh/g have been achieved. In addition this battery exhibited good cycling performance. Considering these results we expected utilization of the Li$_2$O-P$_2$O-V$_2$O$_{5}$ glass as a cathode material in a secondary battery.y battery.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.4
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• pp.55-59
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• 1999

One of lead free glass, Bi based solder glass is investigated for electronic packaging application. The melting temperature of glass about $550^{\circ}C$ at Bi based glass (70wt% $B_2O_3$ + l5wt%$B_2O_3$ + 8wt% $SiO_2$ + 2wt% $P_2O_5$ + 4wt% $A1_2O_3$ +lwt% ZnO) and varied with $P_2O_5$ content in this system. Crystallized glasses were obtainded after 1hr heat teratment at $450^{\circ}C$ with 10wt% of $P_2O_5$ addition. Much higher melting temperature was observed at $B_2O_3$ rich composition area.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.6
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• pp.372-375
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• 2017

ZnO thin films were deposited by RF magnetron sputtering and then diffused by using an As source in the ampouletube. Also, the ZnO p-n homojunction was made by using As-doped ZnO thin films, and its properties were analyzed. After the As doping, the surface roughness increased, the crystal quality deteriorated, and the full width at half maximum was increased. The As-doped ZnO thin films showed typical p-type properties, and their resistivity was as low as $2.19{\times}10^{-3}{\Omega}cm$, probably because of the in-diffusion from an external As source and out-diffusion from the GaAs substrate. Also, the ZnO p-n junction displayed the typical rectification properties of a p-n junction. Therefore, the As diffusion method is effective for obtaining ZnO films with p-type properties.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.8-12
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• 2006

In this paper, reflectance and the dielectric characteristics for $P_2O_5$-ZnO-BaO system and $SiO_2-ZnO-B_2O_3$ system have been investigated as a function of contents of $TiO_2$. The reflectance was decreased with increasing the contents of $TiO_2$ contents, and the reflectance of $P_2O_5$-ZnO-BaO system was lowered than that of $SiO_2-ZnO-B_2O_3$ system. The dielectric constant of $P_2O_5$-ZnO-BaO system was higher than $SiO_2-ZnO-B_2O_3$ system, and the dielectric constant in the both system was increased with increasing of $TiO_2$ contents. This can explained as the space charge effects. These results are could be applied to the lower dielectrics layer of PDP required high reflective ratio and breakdown strength.

• Journal of the Korean Ceramic Society
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• v.22 no.3
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• pp.35-40
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• 1985

The composition of the base glass was determined to be $Na_2O$ 15, $Fe_2O_3$ 35, $B_2O_3$ 0~20, $P_2O_5$ 30~50 by mole percent. The heating temperature for nucleation was determined by means of thermal expansion curve. Crystalline phases were investigated by X-ray diffraction method and I.R Spectra. Electrical conductivities of glass spec-imens were observed in the temperature range 25~20$0^{\circ}C$ The activation energies of these specimens were caculated. The results obtained were as follows : 1) The limit composition of the melts 15mol% $Na_2O$ 35mole% $Fe_2O_5$ 20mole% $B_2O_3$ 30mole% $P_2O_5$ was able to be formed into desired shapes during cooling, . 2) In the measurement of d. c conductivity($\delta$) on the glasses in the system $15Na_2O-35Fe_2O_3$-$B_2O_3$-(50-x) $P_2O_5$ the values decreased by replacing 5 mole% $P_2O_5$ with $B_2O_3$ 3) The d. c conducties of heat treated samples were increased by replacing $P_2O_5$ with $B_2O_3$ 4) $B_2O_3$ contributed to precipitate crystals such as${\gamma}$-$Fe_2O_3$ $Fe_3O_4$ which had the advantage of electronic conduction in heat treated samples. 5) The slope plotted Log($\delta$) versus 1/T in this glass system was linear in the measured temperature range.

• Advances in Traditional Medicine
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• v.7 no.3
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• pp.261-273
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• 2007

We investigated the antihypertensive effect of Pet ether extract (PE) of ginger rhizome; its toluene fraction (TF) and Korean ginseng extract (KGE) in deoxycorticosterone acetate (DOCA) - salt induced and fructose induced hypertensive rats. In DOCA model, DOCA (25 mg/kg, once a week; s.c) was administered in uninephrectomised animals for 4 w. PE (50 mg/kg/day; p.o), TF (10 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) were evaluated for their antihypertensive effect. In the fructose model, drinking water was replaced with fructose (10%) for five weeks to induce hypertension. PE (50 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) were assessed for its antihypertensive effect in fructose model. After completion of the treatment schedule, vascular reactivity to various agonists like 5-HT, noradrenaline, adrenaline, phenylbiguanide and acetylcholine were recorded in rats of both the models. A cumulative dose response curve (CDRC) of 5-HT was carried out in isolated rat fundus strip of the fructose induced hypertensive rats. Chronic administration of PE (50 mg/kg/day; p.o), TF (10 mg/kg/day; p.o), and KGE (30 mg/kg/day; p.o) significantly reduced the blood pressure in DOCA salt whereas PE (50 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) reduced the blood pressure in fructose induced hypertensive rats. Treatment with PE (50 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) in fructose model for five weeks shifted the CDRC towards the right on rat fundus. The mechanism of action may partly involve the serotonergic antagonistic property.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.45-51
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• 2005

$K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$ in the $K_2O-Li_2O-Al_2O_3$ ternary system was synthesized using aluminum nitrate solution as a starting material. For the synthesis of pure $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$, raw materials with chemical composition of $0.84K_2O{\cdot}0.082Li_2O{\cdot}5.2Al_2O_3$ were mixed in solution state. The effects of dispersant and solution-pH were investigated in minimizing the particle size and on the synthesis of pure $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$. Ethanol was used for a dispersant, and $NH_4OH$ solution and nitric acid were added for pH adjustment. The solution pH was increased from 1.0 to 7.5 by 0.5 increments. Each sample was calcined at $1200^{\circ}C$ for 2 h and characterized with X-ray diffraction and particle size analyzer. The pH of solution significantly effected both particle size and phase formation, while the addition of ethanol only effected particle size. The synthesis of pure $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$ was favored by addition of nitric acid (for pH control).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.6
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• pp.575-579
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• 2008

Al-doped p-type ZnO films were fabricated on n-Si (100) and homo-buffer layers in pure oxygen at $450^{\circ}C$ of by RF magnetron sputtering. Target was ZnO ceramic mixed with 2 wt% $Al_2O_3$. XRD spectra show that the Al-doped ZnO thin films have ZnO crystal structure and homo-buffer layers are beneficial to Al-doped ZnO films to grow along c-axis. Hall Effect experiments with Van der Pauw configuration show that p-type carrier concentrations are ranged from $1.66{\times}10^{16}$ to $4.04{\times}10^{18}\;cm^{-3}$, mobilities from 0.194 to $2.3\;cm^2V^{-1}s^{-1}$ and resistivities from 7.97 to $18.4\;{\Omega}cm$. p-type sample has density of $5.40\;cm^{-3}$ which is smaller than theoretically calculated value of $5.67\;cm^{-3}$. XPS spectra show that Ols has O-O and Zn-O structures and Al2p has only Al-O structure. P-ZnO:Al/n-ZnO:Al junctions were fabricated by magnetron sputtering. V-I curves show that the p-n junctions have rectifying characteristics.