Currently, diopside (MgCaSi2O6) crystal glaze is used frequently for pottery works or in earthen wares, though the process is not straightforward. However, to create and control the positions and sizes of the crystals in desired amounts when making pottery is difficult. To solve this problem, a diopside crystal seed was created at a temperature of 1450˚C. After planting this seed in the glaze, a glaze combination and firing process which allows a user to create crystals with the desired position and at the desired size were established. In addition, in order to investigate the creation process of the crystals, the growth patterns of the crystals were observed and examined using Raman spectrography and XRD and SEM analyses. As a result, the optimum synthesis condition of the diopside seed was created by mixing 1 mole of CaCo3, 0.2 mole of (MgCo3)4(MgCoH)2·5H2O and 2 moles of SiO2 and then applying a firing process to the mixture at 1,450˚C for 30 minutes. The optimum glaze content of the seed was 70 % feldspar, 20 % limestone and 10 % MgCo3. For the firing process, it was confirmed that the size of crystal is larger with a longer firing time at 1100˚C by completing a two-hour process at 1280˚C. In addition, the diopside crystal has columnar structure and is less than 1μm in size.

Generally, the color gold has had a biased conception due to its traditional use. Thus, this bias has resulted in alack of usage of golden glaze on ceramics and also a lack of extensive studies of such glazes. In this paper, optimum conditionsand mechanism of formation of gold color crystallization glaze containing Fe2O3(hematite), which is developed for gold colorsof ceramic glazes, were studied. Experimental result showed that there are pyroxene based on diopside and TiO2 phase in thebase of a crystallization glaze with a value of TiO2 of 6wt% confirmed by XRD and Raman Spectroscopy. When Fe2O3 wasused as a colorant for the gold color, the TiO2 peak became extinct and the intensity of the diopside peak was sharper. Feldsparof 60wt%, talc of 20wt% and limestone of 20wt% were used as the starting materials and these were tested using a threecomponent system. The best result of test was selected and extended to its vicinity as an experiment to determine TiO2 andFe2O3 contents. The glaze with TiO2 of 6wt% and Fe2O3 of 12wt% addition showed stable pyroxene based diopside crystalsand the development of gold color. This gold color was obtained with CIE-L*a*b* values of 51.27, 4.46, 16.15 (a grayishyellow brown color), which was gained using the following firing conditions: temperature increasing speed 5oC/min, holdingfor 1h at 1280oC, annealing speed 3oC/min till 1100oC, holding for 2h at 1100oC, and finally natural annealing.

The effects of thermal properties on the crystallization behavior of CaMgSi2O6 glass-ceramics were investigated as a function of sintering temperature from 800˚C to 900˚C. The crystallization behavior of the specimens depended on the sintering temperature, which could be evaluated from the differential thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy. With increasing sintering temperature, the thermal conductivity of the sintered specimens increased, while the coefficient of thermal expansion (CTE) of the sintered specimens decreased. These results could be attributed to the increase of crystallization, confirmed from the estimation by density measurements. Also, the thermal diffusivity and specific heat capacity of the sintered specimens were discussed with relation to the sintering temperature. Typically, a thermal conductivity of 3.084 W/m˚C, CTE of 8.049 ppm/˚C, thermal diffusivity of 1.389 mm2/s and specific heat capacity of 0.752 J/g˚C were obtained for CaMgSi2O6 specimens sintered at 900˚C for 5 h.

한성 비정질 투휘석(Ca,Mg)SiO3에 대한 상변이 연구를 압력은 다이아몬드앤빌기기를 이용하여 ∼30 GPa까지, 온도는 약(YAG) 레이저 가열기기를 이용하여 ∼1000℃에서 조사(scanning)하여 시행하였다. 비정질 투휘석은 고온-고압 하에서 곧바로 등축정계에 속하는 단상의 (Ca,Mg)SiO3페롭스카이트 결정구조로 상변이 하였다. 이러한 결과는 고온-고압 하에서 사방정계에 속하는 MgSiO3페롭스카이트 상과 등축정계에 속하는 CaSiO3페롭스카이트 상으로 분리되는 상변이를 하는 결정질 투휘석의 상변이 계통과는 큰 차이를 보이고 있다. 이러한 차이는 출발시료의 차이점이나 특히 온도가 상변이에 큰 영향인자로 작용하여 기인한 것으로 판단된다. 이러한 강변이 관계는 맨틀의 온도, 압력 및 산소분압 차이 등에 의해 맨틀전이대나 하부맨틀을 구성하는 광물상의 조합에 영향을 줄 수 있다.