Dielectric properties of $0.6Pb(Sc_{1/2}Ta_{1/2})O_3-0.4PbTiO_3$ ceramics prepared by the molten salt synthesis method

용융염 합성법에 의해 제조된 $0.6Pb(Sc_{1/2}Ta_{1/2})O_3-0.4PbTiO_3$ 세라믹스의 유전성

  • Park, Kyung-Bong (School of Advanced Materials Engineering, Andong National University) ;
  • Kim, Tae-Huei (School of Advanced Materials Engineering, Andong National University) ;
  • Kwon, Seung-Hyup (School of Advanced Materials Engineering, Andong National University) ;
  • Lim, Dong-Ju (School of Advanced Materials Engineering, Andong National University)
  • 박경봉 (안동대학교 공과대학 신소재공학부) ;
  • 김태희 (안동대학교 공과대학 신소재공학부) ;
  • 권승협 (안동대학교 공과대학 신소재공학부) ;
  • 임동주 (안동대학교 공과대학 신소재공학부)
  • Published : 2007.04.30

Abstract

[ $0.6Pb(Sc_{1/2}Ta_{1/2})O_3-0.4PbTiO_3$ ] (hereafter PSTT) ceramics were prepared by the molten salt synthesis (MSS) method using KCI as a flux. Formation of perovskite phase was investigated by a differential thermal analysis (DTA) and X-ray diffraction (XRD) analysis in the temperature range from $600^{\circ}C$ to $850^{\circ}C$. A 92% perovskite phase was synthesized at $750^{\circ}C$ for 2 hrs using the MSS method, while 82% perovskite phase was synthesized at $850^{\circ}C$ for 4ks using the calcining of mixed oxide (CMO) method. This result could be due to the improvement in reactivity of $Sc_2O_3$ by melting of KCI. The MSS specimen sintered at $1,100^{\circ}C$ for 4hrs showed a dielectric constant of 11,200, a remnant polarization of $13.5{\mu}C/cm^2$ and a coercive field of 10.198 kV/cm, which was discussed in view of the microstructure.

[ $0.6Pb(Sc_{1/2}Ta_{1/2})O_3-0.4PbTiO_3$ ](이후 PSTT) 세라믹스를 KCI을 flux로 사용한 용융염 합성법을 이용하여 제조하였다. $600^{\circ}C$에서 $850^{\circ}C$까지 온도를 상승시키면서, 시차열분석기와 X-선 회절기를 이용하여 perovskite 상의 형성과정을 조사하였다. 용융염 합성법의 경우 $750^{\circ}C$에서 2시간 하소하였을 때, 92%의 perovskite 상의 생성율을 나타낸 반면, 일반하소법의 경우는 $850^{\circ}C$에서 4시간 하소하였을 때도 82%의 perovskite상의 생성율을 나타내었다. 이는 flux로 사용된 KCI 용융으로 인한 $Sc_2O_3$의 반응성의 향상에 기인한 것으로 생각된다. $1,100^{\circ}C$에서 4시간 소결한 PSTT 시편의 경우, 용융염 합성법으로 제조된 시편이 일반하소법으로 제조된 시편에 비해 큰 11,200의 유전상수와 $13.5{\mu}C/cm^2$의 잔류분극, 10.198kV/cm의 항전계 값을 나타내었으며 이를 미세구조 관점에서 고찰하였다.

Keywords

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