以反應燒結法製備價數補償Ba1-xAx(FeTa)0.5O3陶瓷之結構與介電性質研究(A= Pr、Bi)

本研究係以反應燒結法在不經煆燒步驟下合成複合型鈣鈦礦陶瓷Ba(FeTa)0.5O3 (BFT) 之主體材料，並以不同價數之Pr3+、Bi3+離子來取代Ba2+離子位置，以製備出Ba1-xAx(FeTa)0.5O3(A=Pr、Bi) (x = 0.5 ~ 10 mol%) 之複合型鈣鈦礦強介電陶瓷體，探討其結晶、顯微結構特性與介電性質。以乾式球磨反應燒結法合成Ba1-xAx(FeTa)0.5O3(A=Pr、Bi) (x = 0.5 ~ 10 mol%) 之複合型鈣鈦礦強介電陶瓷體。由研究顯示，BPFT及BBFT陶瓷皆在1300℃燒結8小時可獲得最佳的介電性質。其中Ba0.995Pr0.005(FeTa)0.5O3陶瓷在頻率100 Hz及溫度-20~180℃之介電常數為2×104 ~ 4×105，而Ba0.94Bi0.06(FeTa)0.5O3陶瓷體在頻率100 Hz及溫度-20~180℃之介電常數為1.5×105~2.5×105，所有陶瓷樣品的相對密度都大於95%。且不論BPFT及BBFT摻雜量為多少，其介電值均隨頻率的增加而減少，此表示BPFT及BBFT介電陶瓷為典型強介電弛緩體之介電材料，並在低頻範圍內擁有大量的方向性極化以及空間電荷極化。此外在燒結過程中由於氧空缺在晶界或在晶粒的擴散速度不同，導致晶界的阻抗遠大於晶粒，因此而形成所謂晶界層電容，以致於BPFN 及BBFN 鐵電陶瓷均獲得高介電常數。

關鍵字

反應燒結法； BFT ；高介電材料

並列摘要

In this investigation, an complex perovskite structure, Ba(FeTa)0.5O3 (BFT), was chosen as the host material and doped with trivalence Pr3+ and Bi3+ ions to substitute the Ba2+ ion to form Ba1-xAx(FeTa)0.5O3 (A=Pr, Bi) ceramics prepared using the reaction sintering. In the complex perovskite oxides Ba1-xAx(FeTa)0.5O3(A=Pr, Bi) system, when the Pr3+ ion concentration increasing, the dielectric constant was decreased owing to the Pr3+ would made particle growth difficult and produced porosity increasing. The dielectric constant measured at 100 Hz is about 2×104 ~ 4×105 at room temperature for Ba0.995Pr0.005(FeTa)0.5O3 ceramic sintered at 1300 oC for 8 h. In addition, when Bi3+ ion concentration increasing, the density was increased due to the melting point of Bi2O3 is about 817 oC which could be acted as a flux reagent and increased the relative density. The dielectric constant measured at 100 Hz is about 1.5×105~2.5×105 at 25 oC for Ba0.94Bi0.06(FeTa)0.5O3 ceramic sintered at 1300 oC for 8 h. The relative densities for all the samples are over than 95%. The dielectric relaxor behavior with a broad temperature range was obtained for the BPFT and BBFT ceramics which were contributed by orientation and space charge polarization. The Cole-Cole plot analysis results indicated that the grain boundary-layer capacitance was produced for the Ba1-xAx(FeTa)0.5O3(A=Pr, Bi) system.

並列關鍵字

reaction-sintering process ； BFT ； High dielectric material

參考文獻

[5] S. L. Swartz,T. R. Shrout,W. A. Schulze and L. E. Cross, 1984, "Dielectric Properties of Lead-Magnesium Niobate Ceramics", J. Am. Ceram. Soc. 67 311.

[6] T. T. Fang and H. K. Shiau, 2004, "Mechanism for Developing the Boundary Barrier Layers of CaCu3Ti4O12" J. Am. Ceram. Soc., 87 2072.

[8] Z. Wang, X. M. Chen, L. Ni, Y. Y. Liu and X. Q. Liu, 2007, "Dielectric relaxations in Ba(Fe1/2Ta1/2)O3 giant dielectric constant ceramics", Appl. Phys. Lett. 90 102905.

[10] S. Saha and T. P. Sinha, 2002, "Low-temperature scaling behavior of BaFe0.5Nb0.5O3", Phys. Rev. B: Condens. Matter 65 134103.

[11] 鍾朝宇，2005，"複合型鈣鈦礦Ba1-xAx(Fe0.5Nb0.5)1-x/4O3(A=La、Bi)之介電性質研究"，國立成功大學材料科學及工程博士論文

國際替代計量

以反應燒結法製備價數補償Ba1-xAx(FeTa)0.5O3陶瓷之結構與介電性質研究(A= Pr、Bi)

未授權

主題瀏覽