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Journal of the Korean Ceramic Society 1994;31(11): 1369. |
| 산화물에서의 산소추적자확산계수를 결정하는 새로운 방법의 개발 I- 라만분광법에 의한 분위기가스 중의 시간에 따른 $^{18}O_2$ 농도변화 측정 - |
| 김병국, 하마구찌히로오1, 박순자2 |
서울대학교 무기재료공학과, 일본 카나가와과학기술아카데미
1일본 카나가와과학기술아카데미
2서울대학교 무기재료공학과 |
| Development of Novel Technique for Determining the Oxygen Tracer Diffusion Coefficients in Oxides I - Measurements of the Time Profiles of $^{18}O_2$ Concentration in the Ambient Gas by Raman Spectroscopy - |
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| ABSTRACT |
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A novel technique for determining the oxygen tracer diffusion coefficients in oxides was developed. While the $^{16}O-^{18}O$ solid-gas exchange reactions between $^{16}O$ in the oxides and $^{18}O$ in the ambient gas proceeded, Raman spectra of the ambient gas were measured in a quasi in situ manner through the quartz glass window built in a diffusion apparatus. From thus obtained Raman spectra, time profiles of $^{18}O_2$ concentration in the ambient gas were calculated. The oxygen tracer diffusion coefficients and the surface exchange coefficients were determined under the assumptions that samples are semi-infinite slab and that the surface exchange reactions are not negligible. The oxygen tracer diffusion coefficients of 2.8 mol% $Y_2O_3$-containing tetragonal $ZrO_2$ polycrystals, $TiO_2$ single crystals (along the c axis), and $SrTiO_3$ single crystals (along the a axis) are as follows.$D_{mg.3YSZ}$=1.14$()times10^{-2};exp[-(117.5pm0.4);[KJ/mol]/RT$ $[cm^2/sec];at;700^{circ}C~1165^{circ}C$ $D_{mg,TiO_2//_c}$+5.33$()times10^{-6};exp[-(170.1pm0.5);[KJ/mol]/RT$ $[cm^2/sec];at;1046^{circ}C~1165^{circ}C$ $D_{mg. SrTiO_3//_c}$=5.31$()times10^{-7};exp[-(69.4pm2.8);[KJ/mol]/RT$ $[cm^2/sec];at;700^{circ}C~1100^{circ}C$ The practical upper limit of the eoygen tracer difusion coefficients that can be deterined by this mehtod is ca. $10^5;cm^2/sec.$ |
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