• Title/Summary/Keyword: strontium

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Nb doped strontium titanate single crystal growth by floating zone method (Floating zone법에 의한 Nb를 첨가한 strontium titanate 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.3
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    • pp.215-222
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    • 1995

  • Nb doped strontium titanate single crystals were grown by the floating zone method. The doping amount of $Nb_2O_5$ was 0.2 wt %. Those crystals were grown in air and N z atmosphere and the growth rate was 5 mmlhr and rotation speed of upper and lower shaft was 30 rpm. The shapes of melt - feed rod interface depending on sintering temperatures were observed. In air atmosphere, the flow rate of air was 1.5 ${\ell}/min$ and in $N_2$ atmosphere, that of $N_2$ gas was 0.5 ${\ell}/min$. As grown crystals were analyseQ by XRD, Laue back - reflection and chemical etching. After annealing in $N_2$ atmosphere, resistivities of crystals were measured and the activation energies of each samples were calculated.

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Separation of Radiostrontium from Environmental Sample Using Strontim Selective Chromatographic Resin$(Sr.\;Spec^{TM})$ (스트론튬 선택적이온교환수지$(Sr.\;Spec^{TM})$를 이용한 환경시료중의 방사성 스트론튬의 분리)

  • Hong, Kwang-Hee;Lee, Chang-Woo;Choi, Yong-Ho;Lee, Myung-Ho
    • Journal of Radiation Protection and Research
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    • v.20 no.1
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    • pp.1-7
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    • 1995

  • Strontium selective chromatographic material $(Sr-Spec^{TM})$ was investigated for separation of radiostrontium from environmental soil and water sample. This chromatographic material has great capacity of binding of strontium ion in nitric acid media, and has selectivity to permit the separation of stontium from bulk amount of calcium. But the extraction of strontium was reduced by the other interfering ions such as K and Ba. So, in order to apply this material to the soil sample, prior removal treatment of K and Ba was needed. But the Sr-Spec material could provides simple and effective methods for the separation and removal of radiostrontium from liquid sample.

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