Grain Growth Anomaly and Dielectric Response in Ti-rich Strontium Titanate Ceramics

abstract

A grain growth anomaly in Ti-rich strontium titanate ceramics is reported. Here we show that three discontinuities on the temperature dependence of grain growth take place with drops in the grain size at temperatures around 1500, 1550, and 1605 degrees C. We also show that similar discontinuities can be observed in the dependence of the grain boundary activation energy for conductivity and in the grain boundary thickness, assessed by impedance spectroscopy (IS). These notable coincidences are reported for the first time and strongly support the formation of different grain boundary complexions in polycrystalline oxides with transitions in between the observed grain growth regimens, which may be correlated to different grain boundary mobility and dielectric properties. These results call into question the discussion on the role of nonstoichiometry of SrTiO3 and complexions on the microstructure development and open opportunities to design properties of functional materials.

keywords

BOUNDARY DEFECT CHEMISTRY; ACCEPTOR-DOPED TITANATES; BARIUM-TITANATE; IMPEDANCE SPECTROSCOPY; SPACE-CHARGE; SRTIO3; MICROSTRUCTURE; COMPLEXION; KINETICS; LAYER

subject category

Chemistry; Science & Technology - Other Topics; Materials Science

authors

Amaral, L; Fernandes, M; Reaney, IM; Harmer, MP; Senos, AMR; Vilarinho, PM

our authors

acknowledgements

The authors thank Jian Luo and Animesh Kundu for the helpful discussion of the results. The authors acknowledge the financial support from FEDER, QREN, COMPETE, FCT, and the Foundation for Luso American Development (FLAD), Portugal. Luis Amaral acknowledges FCT for financial support (SFRH/BD/40927/2007).

Share this project:

Related Publications

We use cookies for marketing activities and to offer you a better experience. By clicking “Accept Cookies” you agree with our cookie policy. Read about how we use cookies by clicking "Privacy and Cookie Policy".