Browsing by Author "Park, Y.J."

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Correlation between glaze-colors and structural properties of the HIZEN celadons produced in the Edo period of Japan, by means of X-ray diffraction (?)
(Cer?mica, 2011) Hidaka, M.; Ohashi, K.; Wijesundera, R.P.; Kumara, L.S.R.; Watanabe, M.; Koga, K.; Choi Jae-Young; Sung, N.E.; Park, Y.J.
HIZEN celadons produced at Arita and Imari areas in Japan from 1630's to 1790's (Edo period) have been investigated by means of X-ray fluorescence analysis, and X-ray diffraction and X-ray absorption spectra using synchrotron radiation. It is found that, in the HIZEN celadons, the color brightness of the celadon glazes depends on the structural property of the raw basic ceramics taken at Imaizumi (Arita) and Ohkwachi (Imari), where the former is mainly Quartz-SiO2, and the later is Sanidine ((K,Na)Si3O8). It is confirmed that CaCO3 of natural wood ash added artificially into the raw celadon ceramics makes a glassy glaze on the surface of the basic body of the HIZEN celadons. Transition-metal ions (Cr, Cu, Zn) of very small amount are detected in the celadon glazes, in addition to Fe and Mn of small amount. It is considered that Cu and Cr are related to the color brightness of green-brown and blue-green in the HIZEN celadon glazes, respectively.
Correlation between the Izumiyama porcelain ceramics and the red-overglaze enamels of the Kakiemon-style porcelains
(Ceramics International, 2008) Kajihara, S.; Hidaka, M.; Wijesundera, R.P.; Kumara, L.S.R.; Kobayashi, H.; Koga, M.; Tsuru, T.; Koga, K.; Shimomura, K.; Choi Jae-Young; Sung, N.E.; Park, Y.J.
The Kakiemon-style porcelains made from 17th century at Arita are famous Japanese porcelains, characterized mainly by their colored underglaze and overglaze and by their original design of coloring spatial patterns in the porcelain surface. Raw materials of the red-overglaze enamels have been investigated by means of X-ray diffraction and X-ray absorption spectra using synchrotron radiations. It is found that Izumiyama porcelain ceramics of yellow color can produce the Kakiemon red-overglaze enamels by thermal treatment and water-washing, where Izumiyama is a collecting place of the raw porcelain ceramic at Arita. The brightness of the red-overglaze enamels is related on the local structure around Fe ions and the electronic band states of Fe ions near a Fermi level in ?-Fe2O3, in addition to the spatial density of the ?-Fe2O3 fine particles. The structural and electronic properties are slightly affected by an electron-hybridization between Fe ions of ?-Fe2O3 and oxygen ions of the (SiO2?Al2O3) complexes in the red overglaze.
Order-disorder transitions of t2g-orbitals of V3+ ions and incommensurate structural deformations in the metallic spinel CuV2S4
(Physica Status Solidi b (basic solid state physics), 2007) Hidaka, M.; Tokiwa, N.; Wijesundera, R.P.; Awaka, J.; Nagata, S.; Park, Y.J.; Lee, K.B.
Structural transitions of the spinel CuV2S4 have been studied by means of X-ray diffraction using synchrotron radiation. The temperature dependence of reflections forbidden in a cubic spinel structure of Fd3m suggests that there are order?disorder transitions of 3d2 (t2g) orbitals of V3+ ions at about 75 and 210 K. An incommensurate superlattice reflection of (2+3/4, 2, 2+3/4) shows the structural phase transition occurring at about 90 K, in addition to the superlattice structural modulation at about 30?35 and 55 K. A reduced wavevector q = (3/4??, 0, 3/4??) shows the temperature dependence of the ? value from 0.015 to ?0.025. A lock-in of ? = 0.0 and a crossover of the ? value occur in the region of 40 to 50 K. The incommensurate structural modulation along [110], [011], and [101] directions appearing below about 90 K affects a paramagnetic spin order of V3+ ions at about 30?35 and 55 K, in addition to the 90 K structural transition. The paramagnetic behavior is interpreted mainly by the structural deformation and the (dxy, dyz, dzx) orbitals in the VS6 octahedral chains sited along [110], [011], and [101] directions.
Structural properties of the red-color overglazes on the Kakiemon-style porcelains produced in the later 17th century by means of X-ray diffraction (I)
(Cer�mica, 2009) Hidaka, M.; Horiuchi, H.; Ohashi, K.; Wijesundera, R.P.; Kumara, L.S.R.; Choi Jae-Young; Park, Y.J.
Kakiemon-style porcelains produced at Arita areas (SAGA) in Kyushu Island are famous Japanese porcelains. The porcelain-techniques creating its elegant and bright red-color underglaze and overglaze were found and developed in 1650's (early Edo period) first by Kakiemon kiln. Red-color overglaze and transparent glaze of the Kakiemon-style porcelains have been investigated by means of X-ray diffraction using synchrotron radiation. The results suggest that the red-color brightness is mainly induced by micro-structural correlation between ?-Fe2O3 fine particles, as red-color emission elements, and other oxides of SiO2, Al2O3, CaO, KNaO, PbO. The stability of the red-overglaze on the porcelain surface is related to interfacial fusion of the glasses existing in the fritted red-overglaze and the transparent glaze on the porcelain body. The ancient porcelain-techniques of the Kakiemon-style porcelains are clearly based on the micro-structural and material properties of the overglazes, the underglazes, and the transparent glazes, though the techniques were experimentally and accidentally found and developed in the Edo period.