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In Situ Electron Holography of Grain Boundary Schottky Barrier Dynamics in 0.5 Wt% NB Doped SrTiO3 36.8° Symmetric Tilt Bicrystals

Published online by Cambridge University Press:  02 July 2020

K.D. Johnson  and
V.P. Dravid
K.D. Johnson
Affiliation:
Department of Materials Science & Engineering, Northwestern University, Evanston, IL60208
V.P. Dravid
Affiliation:
Department of Materials Science & Engineering, Northwestern University, Evanston, IL60208
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Extract

Electrical phenomena such as positive temperature coefficient of resistance (PTCR), grain boundary layer capacitance, and varistors are controlled by Schottky barriers to current transport formed in grain boundary regions. These grain boundary potential barriers are a result of charged defect accumulation, either through equilibrium segregation or kinetic diffusion processes. Recent work on Nb and Mn doped BaTiO3 highlights the importance of substitutional defects which activate grain boundary trap states and give rise to the PTCR effect. The dynamic interaction of charge carriers with such trap states also produces the rapid electrical breakdown characteristic of varistors. This study explores the issues of defect species, space charge, and electrical transport in donor doped SrTi03 by electron holography and electron energy loss spectroscopy.

The specific defect species and mechanisms of current transport through donor doped SrTiO3 remain unresolved because of the difficulty in connecting defect distributions (structural information) and resultant Schottky barrier effects (chemical information).

Type
Spatially-Resolved Characterization of Interfaces in Materials
Information
Microscopy and Microanalysis , Volume 4 , Issue S2: Proceedings: Microscopy & Microanalysis '98, Microscopy Society of America 56th Annual Meeting, Microbeam Analysis Society 32nd Annual Meeting, Atlanta, Georgia July 12-16, 1998 , July 1998 , pp. 796 - 797
Copyright
Copyright © Microscopy Society of America

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References

1.Miki, T. et al., J. Appl. Phys., 83, [3],(1998), pp.1592–1603.CrossRefGoogle Scholar
2.Gaucher, P. et al., Adv. Cer. Mats., 3, [3], (1988), pp. 273-77.Google Scholar
3.Ravikumar, V. et al., J. Am. Ceram. Soc, 80, [5], (1997), pp. 1117-38.CrossRefGoogle Scholar
4. This research is supported by US DOE (Grant No. DE-FG02-92ER45475).Google Scholar