Pb(Fe1/2Ta1/2)O3-Pb(Fe1/2Nb1/2)O3 고용체의 유전특성 및 질서배열구조 |
우병철, 김병국1, 이종호1, 박현민, 김병호2 |
한국표준과학연구원 물질량표준부 1한국과학기술연구원 재료연구부 2고려대학교 재료공학부 |
Dielectric Properties and Ordering Structures of Pb(Fe1/2Ta1/2)O3-Pb(Fe1/2Nb1/2)O3 Solid Solutions |
Byong-Chul Woo, Byung-Kook Kim1, Jong-Ho Lee1, Hyun-Min Park, Byong-Ho Kim2 |
Division of Chemical Metrology and Materials Evaluation, Korea Research Institute of Standards and Science 1Division of Materials, Korea Institute of Science and Technology 2Division of Materials Science and Engineering, Korea University |
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ABSTRACT |
The Single phase $Pb(Fe_{1/2}Ta_{1/2})O_3$ (x=0.0∼1.0) solid solutions were successfully synthesized and their ordering structures as well as dielectric properties were investigated ${{r(Nb^{5+})=r(Ta^{5+})=0.78 {AA},;AW(Nb^{5+})=92.91,;AW(Ta^{5+})=180.95}}$. While $Pb(Fe_{1/2}Ta_{1/2})O_3$ showed typical relaxor ferroelectric characteristics such as dielectric relaxation and diffuse phase transition, the sharpeness of the phase transition increased as $Ta^{5+}$ was replaced by $Nb^{5+}$ and finally $Pb(Fe_{1/2}Nb_{1/2})O_3$ showed normal ferroelectric characteristics with no dielectric relaxation. By using Raman spectroscopy, it was revealed that the $Fe^{3+};and;Ta^{5+};of;Pb(Fe_{1/2}Ta_{1/2})O_3$ were stoichiometrically 1:1 ordered within the short range which can be hardly probed even by TEM. Also, The degree of ordering in $Pb(Fe_{1/2}Ta_{1/2})O_3$ decreased as $Ta^{5+}$ was replaced by $Nb^{5+}$ and finally $Fe^{3+};and;Nb^{5+};of;Pb(Fe_{1/2}Nb_{1/2})O_3$ were completely disordered. The relaxor ferroelectric characteristics of $Pb(Fe_{1/2}Ta_{1/2})O_3$ could be correlated with the stoichiometric 1:1 ordering of B-site cations within the short range which can be hardly probed even by TEM. Also, the decrease of the relaxor ferroelectric characteristics with the replacement of $Ta^{5+};by;Nb^{5+}$ could be correlated with the weakening of the ordering and the normal ferroelectric characteristics of $Pb(Fe_{1/2}Nb_{1/2})O_3$ could be correlated with the complete disordering of B-site cations. |
Key words:
Lead iron niobate, Lead iron tantalate, Relaxor, Ordering structure |
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