• 제목/요약/키워드: Inorganic crystal

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$SrTiO_3$ Single Crystal Growth by Verneuil Method (Verneuil법에 의한 $SrTiO_3$ 단결정 성장)

  • Choi, I.S.;Cho, H.;Choi, J.K.;Orr, K.K.
    • Journal of the Korean Ceramic Society
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    • v.29 no.9
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    • pp.689-694
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    • 1992
  • Strontium Titanate single crystal is grown by Verneuil method. Feed materials were prepared by coprecipitation method which started with Sr(NO3)2 and TiCl4. SrTiO3 can not be grown from feed materials having the stoichiometric components due to volatilization of SrO, when the powder added more 3 wt% SrO used, the crystal can be grown. Growth conditions that the pressure of oxygen and hydrogen gas was 5 psi, the flow rate of oxygen and hydrogen was 7.3 and 30ι/min respectively, the growth rate was 20 mm/hr were optimum. The grown single crystal has the diameter of 10~15 mm and its length is 30~40 mm. The grown crystal was deep brown color and somewhat transparent. The color of grown crystal was lightened after annealing.

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Enhanced Crystallization of Amorphous Silicon using Electric Field

  • Song, Kyung-Sub;Jun, Seung-Ik;Park, Sang-Hyun;Park, Duck-Kyun
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1997.06a
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    • pp.243-246
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    • 1997
  • A new technique for low temperature crystallization of amorphous silicon, called field aided lateral crystallization(FALC) was attempted. To demonstrate the concept of FALC, thin layer of nickel(30${\AA}$) was deposited on top of amorphous silicon film and the electric field was applied during the crystallization. The effects of electric field on the crystallization behavior of amorphous silicon film were investigated.

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Silicon single crystal growth by continuous growth method (연속성장법에 의한 silicon 단결정 연속 성장)

  • J.W. Han;S.H. Lee;Keun Ho Orr
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.2
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    • pp.111-118
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    • 1994
  • Silicon single crystals were continuously grown by a modified process. Polycrystalline silicon powder was fed from the top reservoir to the growth chamber. Silicon single crystals were grown from the botton of the growth chamber. The balance between the gravitational force of melt and the centrifugal force originated from the rotation of seed was the one of the main factors to control the diameter of crystals grown and quality, etc.

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Crystal growing of NaX type zeolite

  • Ha, Jong-Pil;Seo, Dong-Nam;Jung, Mi-Jeong;Moon, In-Ho;Cho, Sang-Joon;Park, Hyun-Min;Kim, Ik-Jin
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.4
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    • pp.371-376
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    • 1999
  • A large NaX type zeolite crystal of a uniform particle size of 20$\mu\textrm{m}$ are grown with various {{{{{H}_{2}O}}}} content by hydrothermal reaction and added seed crystal (2~3$\mu\textrm{m}$) to reactant solution as a function of different adding seed levels from 3 to 15%. The result that increased purity of NaX zeolite above 95% and homogeneity of crystal size by increasing adding seed levels, also decreased crystallization time. It was explained that adding seed to synthesis solution leaded out increase of surface area for physical contact reaction and directed growth of seed crystal, so more rapid consumption of reaction gel as increase seeding levels.

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$SrTiO_3$ single crystal growth by floating zone method (Floating zone 법에 의한 $SrTiO_3$단결정 성장)

  • Jeon, Byong-Sik;Cho, Hyun;Orr, Keun-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.2
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    • pp.87-93
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    • 1995
  • Strontium titanate single crystal was grown by floating wne method. Growth conditions are as follows; at air atmosphere, rotation rate of upper and lower shafts were 20 - 25 rpm, 15 - 20 rpm respectively and growth rate was 3 mmlhr. As grown crystal was light brown color and transparent. After annealing, color was faded away. Growth direction was [112] direction and it was confirmed that grown crystal has $SrTiO_3$single phase and stoichiometric composition by XRD and EDS. Etch pit pattern was investigated after chemical etching in $350^{\circ}C$, KOH solution for 5 min and dielectric constant was measured at the range of room temperature ~ $350^{\circ}C$ .

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Correlation defects of macrostructure with morphology of BGO crystals grown by low thermal gradient Czochralski technique

  • Shlegel, V.N.;Shubin, Yu.V.;Ivannikova, N.V.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.13 no.1
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    • pp.1-4
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    • 2003
  • In the present work we consider morphological structure of the faces of BGO crystals grown by Czochralski technique under the conditions of low temperature gradient (0.1~1 deg/cm) and interconnection between the morphological features of faces at the crystallization front and the formation of defects within the crystal volume. It is demonstrated that the {112} faces retain stability while the growing surface deviates from the crystallographic (112) plane up to 1 degree. At larger deviation, the region of the stable facet growth passes either to the region of macrosteps or to the region of normal growth. depending on conditions.