Synthesis, Structure, and Properties of Bi3.25Pr0.75Ti2.97V0.03O12 Ferroelectric Ceramics
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- 作者：Hongchu Du ; Sebastian Wohlrab ; Stefan Kaskel
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：July 26, 2007
- 年：2007
- 卷：111
- 期：29
- 页码：11095 - 11103
- 全文大小：441K
- 年卷期：v.111,no.29(July 26, 2007)
- ISSN：1932-7455
文摘
Praseodymium and vanadium cosubstituted Bi4Ti3O12 was synthesized using a modified citrate-gel method.The crystallization was promoted by the oxidation of residual carbon produced by decomposition of -CHxgroups resulting in a crystallization temperature as low as 450 
C. The as-synthesized powder consisted ofuniform spherical particles with a mean size of 57 nm and a standard deviation of 14 nm. The ceramicprepared from the as-synthesized powder at 900 C consisted mainly of randomly arranged platelets with athickness of 200 nm. The Rietveld refinement in the orthorhombic space group Aba2 for the as-prepared Pr3+and V5+ cosubstituted Bi4Ti3O12 resulted in a convergent refinement (Rwp = 5.01%). The remanent polarization(2Pr) and coercive field (2Ec) values measured at room temperature with a maximum electric field of ±300kV/cm were 35 
C/cm2 and 148 kV/cm, respectively. The ceramic has a very low ohmic conductivity, andthe leakage current density is below 1 A/cm2 up to 200 kV/cm. No profound fatigue was observed afterswitching over 108 cycles. The evolution of 2Ec, 2Pr, Pmax (maximum polarization), and Pmax/Pr with Emax(maximum electric field) is discussed using an ideal and a four components ferroelectric capacitor model.The observed linear relationship between Pmax/Pr and Emax provides the possibility to calculate the fieldindependent dielectric constant (282) and nonremanent polarization (2.7 C/cm2 at Emax = 300 kV/cm) forthe ceramic studied.
C. The as-synthesized powder consisted ofuniform spherical particles with a mean size of 57 nm and a standard deviation of 14 nm. The ceramicprepared from the as-synthesized powder at 900 C consisted mainly of randomly arranged platelets with athickness of 200 nm. The Rietveld refinement in the orthorhombic space group Aba2 for the as-prepared Pr3+and V5+ cosubstituted Bi4Ti3O12 resulted in a convergent refinement (Rwp = 5.01%). The remanent polarization(2Pr) and coercive field (2Ec) values measured at room temperature with a maximum electric field of ±300kV/cm were 35 C/cm2 and 148 kV/cm, respectively. The ceramic has a very low ohmic conductivity, andthe leakage current density is below 1 A/cm2 up to 200 kV/cm. No profound fatigue was observed afterswitching over 108 cycles. The evolution of 2Ec, 2Pr, Pmax (maximum polarization), and Pmax/Pr with Emax(maximum electric field) is discussed using an ideal and a four components ferroelectric capacitor model.The observed linear relationship between Pmax/Pr and Emax provides the possibility to calculate the fieldindependent dielectric constant (282) and nonremanent polarization (2.7 C/cm2 at Emax = 300 kV/cm) forthe ceramic studied.