Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference (한국전기전자재료학회:학술대회논문집)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
권호 표지

A Study on the Ordering of Na ions in N $a_x$W $O_3$(0.5$\leq$TEX>$\chi$$\leq$1.0)

N $a_x$W $O_3$(0.5$\leq$TEX>$\chi$$\leq$1.0)의 Na ion의 규칙화에 관한 연구

  • Na, Jong-Chul (Dept. of Materials Science and Engineering, Korea University) ;
  • Nahm, Sahn (Dept. of Materials Science and Engineering, Korea University) ;
  • Byun, Jae-Dong (Dept. of Materials Science and Engineering, Korea University) ;
  • Kim, Myong-Ho (Dept. of Materials Science and Engineering, Changwon National University) ;
  • Lee, Hwack-Joo (New Materials Evaluation Center, Korea Research Institute of Standards and Science) ;
  • Ryu, Hyun (New Materials Evaluation Center, Korea Research Institute of Standards and Science)
  • 나종철 (고려대학교 재료공학과) ;
  • 남산 (고려대학교 재료공학과) ;
  • 변재동 (고려대학교 재료공학과) ;
  • 김명호 (창원대학교 재료공학과) ;
  • 이확주 (한국표준연구원 신소재개발센타) ;
  • 류현 (한국표준연구원 신소재개발센타)
  • Published : 1996.11.01
Download PDF
⟨ Previous Next ⟩

Abstract

Crystal structures of N $a_{x}$W $O_3$(0.5$\leq$x$\leq$1.0) were investigated. Transmission electron microscopy (TEM) studies indicate that there is an ordering of sodium ions when x=0.75. The direction of ordering is [110] and the wavelength of ordering is twice of the interplanar distance of (110) plane. It has been confirmed that a superlattice containing eight N $a_{0.75}$W $O_3$is the unit cell of ordered structure. In this unit cell, Na sites at (100) and ($\frac{1}{2}$$\frac{1}{2}$$\frac{1}{2}$) are vacant. The ordered phase was preserved after the annealing at $600^{\circ}C$ in the air. In reduced N $a_{x}$W $O_3$with x=0.5 and 1.0, extra phases were found to coexist with the partially ordered perovskite phase. After annealing at $600^{\circ}C$, theses phases were transformed into the phases found in calcined specimens.ens.s.

Keywords