• 한국결정성장학회지
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• 제12권5호
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• pp.234-239
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• 2002

하소온도를 $1000^{\circ}C$ ~ $1300^{\circ}C$ 로 변화시킨 스피넬 분말을 용융침투법으로 스피넬-유리 치관용 복합체를 제조하여 하소온도가 복합체에 기계적 특성에 미치는 영향을 조사하였다. 하소온도가 상관없이 분말의 평균 입도는 2.8 ~3.0 $\mu$m로 유지하다가 $1300^{\circ}C$ 에서 4.66 $\mu$m로 증가하였다. 하소온도가 증가하메 따라 전성형체의 수축률과 기공크기는 각각 감소하고 증가하였다. 따라서, 하소온도에 의한 분말의 입도 및 입도 분포가 치밀화에 지대한 영향을 미치는 것으로 추정된다. 최적의 기계적 특성을 가진 스피넬-유리 복합체의 하소온도는 $1200^{\cire}C$이었으며, 강도와 인성 값은 각각 284$\pm$40 MPa, 2.5$\pm$0.1 MPa $m^{1/2}$이었다. 투광성 실험결과, 상용 알루미나-유리 복합체보다 가시광선 영역에서 투과율이 두배이상 우수한 심미성이 관찰되었다.

• 한국광물학회:학술대회논문집
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• 한국암석학회.한국광물학회 2000년도 공동학술발표회 논문집
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• pp.19-19
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• 2000

;Ultramafic xenoliths found in alkali basalts from Jeju-do, Korea are mostly spinel Iherzolites composed of olivine, orthopyroxene, clinopyroxene and spinel. A subordinate amount of spinel harzburgites and pyroxenites are also found. Temperatures for these xenoliths were estimated from the compositions of coexisting pyroxenes (Wood '||'&'||' Banno 1973; Wells 1977; Bertrand '||'&'||' Mercier 1985; Brey '||'&'||' Kohler 1990), the AI-solubility in orthopyroxene coexisting with olivine and spinel (Sachtleben '||'&'||' Seck 1981; Webb '||'&'||' Wood 1986), and from Fe/Mg partitioning between olivine and spinel (Ballhaus et al. 1991). Temperature estimates from the thermometers by Wells (1977) and Brey and Kohler (1990) are compatible. Average equilibrium temperatures by these two methods for spinel peridotites range from 890 to 1030$^{\circ}$C. Pressures for spinel peridotites were estimated from the geobarometer by Kohler and Brey (1991) derived from the equilibrium Ca content of olivine coexisting with clinopyroxene, and fall within the range of 12.9 to 26.3 kbar. The combination of the thermometer by Brey and Kohler (1990) and the geobarometer by Kohler and Brey (1991) yields P- T estimates for Jeju-do spinel peridotites that fall in experimentally determined spinel lherzolite field in CFMASCr system (O'Neill 1981). These P-T data sets have been used to construct the Quaternary Jeju-do geotherm, which is significantly different from the conventional conductive geotherm. The xenolith-derived geotherm has a higher T gradient at low P (13 kbar) than at high P, which may be due to perturbation of the conductive heat flow by magma underplating or overplating at the crust-mantle boundary. Temperature estimates and statistics on the xenoliths indicate that the crust/mantle boundary in Jeju-do lies at about 11 kbar (~39 km). Spinellherzolite is inferred as a main constituent rock of the uppermost lithospheric mantle beneath Jeju-do. Pyroxenites were intercalated in peridotites in similar depth and temperature as re-equilibrated veins or lens.

• 광물과 암석
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• 제36권4호
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• pp.365-376
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• 2023

제주도 응회환 중 하나인 송악산은 약 3800년 전에 형성되었고, 송악산의 조면현무암에는 스피넬 페리도타이트라는 맨틀암석이 포획되어 있다. 스피넬 페리도타이트의 크기는 2 cm 이하이고, 감람석, 사방휘석, 단사휘석, 스피넬로 구성되어져 있다. 스피넬 페리도타이트 구성광물들의 중심부와 연변부의 화학조성이 유사한 것은 스피넬 페리도타이트가 모암 마그마에 포획되기 전 평형상태에 있었다는 것을 의미이다. 평형온도는 지하 약 55~60km 깊이에서 약 915~968℃ 이다. 네오블라스트 광물을 많이 함유하고 있는 스피넬 페리도타이트는 잔쇄반상조직을 보이고, 구성광물 중 감람석이 킹크밴드를 보이는 것은 송악산 상부맨틀이 변형 받았음을 지시한다. 약 5~7%의 분별용융작용과 규산염 용융체에 의한 은폐교대작용을 경험한 송악산 스피넬 페리도타이트는 모암 마그마에 포획된 후 약 15일이라는 빠른 기간 만에 지표에 올라왔다.

• 공업화학
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• 제21권5호
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• pp.590-592
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• 2010

본 연구에서는 리튬 2차 전지의 양극물질 중 하나인 Li-Mn spinel ($LiMn_2O_4$)을 합성하기 위해 전구체로 K-Birnessite ($K_xMnO_2{\cdot}{yH_2O}$)를 이용하였다. K-Birnessite는 과망간산칼륨[$KMnO_4$]과 우레아[$CO(NH_2)_2$]를 사용하여 수열합성법으로 합성하였고, K-Birnessite와 LiOH를 수열 반응시켜 Li-Mn spinel 나노입자를 제조하였다. 리튬함량에 따른 Li-Mn spinel 의 구조 및 형상 변화와 전기화학적 특성에 대한 경향성을 알아보기 위해 LiOH와 K-Birnessite의 몰 비를 조절하여 Li-Mn spinel를 합성하였다. 합성된 분말은 X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetry (TG)를 이용하여 물질의 구조 및 형상을 분석하였고, 정전류법으로 양극재의 용량과 율 특성을 비교 분석하였다. 그 결과 LiOH/K-Birnessite의 몰 비가 0.8일 때 가장 큰 용량($117\;mAhg^{-1}$)을 나타냈고, 몰 비가 증가할수록 Li-Mn spinel 중 리튬함량이 증가하여 용량은 감소하였으나, 입자크기는 작아져서 율 특성은 점점 향상되는 경향을 보였다.

• 한국세라믹학회지
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• 제27권2호
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• pp.155-160
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• 1990

Al-rich Mg-Al spinel single crystals were grown by Verneuil process using oxygen and hydrogen flame. Spinel single crystals were grown in chemical compositions from MgO : Al2O3 mole ratio 1 : 1 to 1 : 3. Mole ratio 1 : 1 was hard to be grown and mole ratio 1 : 2.5 and 1 : 3 were grown well. Selecting well-grown mole ratio 1 : 3, seeds were prepared having [100], [110] and [111] orientation respectively. Growth rate were highest in [100] orientation and lowest in [111] orientation.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
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• pp.27-30
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• 2007

Martian meteorites are the only available Martian Materials on Earth. A suite of demagnetization experiments, temperature dependence of saturation magnetization, scanning electron microscopy, and electron microprobe analysis were carried out to characterize the remanent magnetization carriers of Martian meteorite SaU 008. A stable paleomagnetic record of SaU 008 originates from a newly found spinel ((Fe, Cr, Ti)-spinel) whose composition has never been documented (or identified as magnetic).

• 한국세라믹학회지
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• 제26권2호
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• pp.187-194
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• 1989

Synthesis of spinel pigment on ZnO-Fe2O3 system. The object of this research is the synthesis of new spinel pigments on the basic of ZnO-Fe2O3 system which was substituted by ZnO-Fe2O3 by MgO-Al2O3. This research was progressed by measuring the X-ray diffraction and the reflectances of the substitued ZnO-Fe2O3 group. Which was obtained by sintering at the temperature of 1,00$0^{\circ}C$, 1,10$0^{\circ}C$, 1,20$0^{\circ}C$ and 1,25$0^{\circ}C$ and them by regrinding. In order to coloring test, here basic compositions of Barium glaze, Zinc glaze, Lime glaze, Lead glaze and Talc glaze used in this experiment are obtained from the ceramic work. Adding synthetic stains in these basic glazes with 3%, mixing and glazing on the specimen. The specimens was fired at 1,28$0^{\circ}C$ in reducing and oxidizing atmosphere in the gas kiln. The results of the research as follow. 1. Many kinds of spinel pigment was produced on ZnO-Fe2O3 system that is to say, not always only spinel. 2. Spinel peak was observed strongly on the ZnO-Fe2O3 system withsubstituting by MgO-Fe2O3 and MgO-Al2O3 group(the ratio of MgO, Al2O3 being increased, observed more strongly). 3. The most effective temperature ranges was 1,20$0^{\circ}C$~1,25$0^{\circ}C$. 4. The color of spinel pigments on this system was observed by "stable YR". 5. It was yellow red in oxidizing and green in reducing atmosphere on the coloring test.ring test.

• 자원리싸이클링
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• 제9권5호
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• pp.11-15
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• 2000

The sample made of $Mn_3O_4$ indicated an excellent frequency dependency for intial permeability and core loss. Moreover the homogeneity of cation configuration in he spinel structure was confirmed by X-ray diffraction analysis. The result of homogeneity of the spinel structural coincided with the analytical results of temperature dependence of magnetization. Furthermore, the influence of manganese oxide as starting material, on homogeneity of spinel structure was examined by using thermogravimetry-differential thermal analysis. It may be concluded that the reaction between $Mn_3O_4$ and Fe-Zn oxide mixture proceeds at fist in all combination of manganese oxide and oxie mixture, and then Mn-Zn-Fe spinel was formed.

• 한국세라믹학회지
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• 제31권2호
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• pp.213-219
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• 1994

The formations of spinel and colors of ZnO-Fe2O3-TiO2-SnO2 system have been researched on the basis of ZnO-Fe2O3 system. Specimens were prepared by substituting Fe3+, with Ti4+ or Sn4+ when mole ratios between Fe3+ and Ti4+ or between Fe3+ and Sn4+ were 0.2 mole. The reflectance measurement and X-ray diffraction analysis of the formation of spinel and the colors of there specimens were carried out. ZnO-Fe2O3 system in which Fe2O3 was substituted with SnO2 and TiO2 was formed the spinel structure of 2ZnO.TiO2, 2ZnO.SnO2, ZnO.Fe2O3. The stable stains which were colored with yellow and brown could be manufactured.

• 한국세라믹학회지
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• 제35권7호
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• pp.671-678
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• 1998

Hertzian indentation tests with sphere indenters were used to study the mechanical properties of glass-in-filtrated alumina and spinel composites and evaluated the effect of preform microstructure and evaluated the effect of preform microstructure and glass con-tents on contanct damage and strength. The spinel composite showed more brittle behavior than the alumina composite which is verified from indentation stress-strain curve cone cracks and quasi-plastic deformation developed at subsurface. Failure originated from either cone cracks(brittle mode) or deformation zone(quasi-plastic mode) above critical load for cracking(Pc) and yield ({{{{ {P }_{Y } }}) with the brittle mode more dominant in the spinels and the quasi-plastic mode more dominant in the aluminas. Even though brittle mode was dominant in the spinel composites the strength degradation from accumulation of damage above these critical loads was conspicuously small suggesting that the glass-infiltrated composites should be highly damage tolerant to the blunt contacts.