Structural variability of edge dislocations in a SrTiO 3 low-angle [001] tilt grain boundary
- PDF / 1,941,288 Bytes
- 9 Pages / 584.957 x 782.986 pts Page_size
- 21 Downloads / 190 Views
Miaofang Chi Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, California 94550; and Department of Chemical Engineering and Materials Science, University of California Davis, Davis, California 95616
Daniel J. Masiel Department of Chemical Engineering and Materials Science, University of California Davis, Davis, California 95616
John P. Bradley Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, California 94550
Bin Jiang FEI Company, Hillsboro, Oregon 97124
Henning Stahlberg Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
Nigel D. Browning Department of Chemical Engineering and Materials Science, University of California Davis, Davis, California 95616; and Condensed Matter and Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (Received 31 October 2008; accepted 25 March 2009)
Using a spherical aberration (Cs)-corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS), we investigated a 6 low-angle [001] tilt grain boundary in SrTiO3. The enhanced spatial resolution of the aberration corrector leads to the observation of a number of structural variations in the edge dislocations along the grain boundary that neither resemble the standard edge dislocations nor partial dislocations for SrTiO3. Although there appear to be many variants in the structure that can be interpreted as compositional effects, three main classes of core structure are found to be prominent. From EELS analysis, these classifications seem to be related to Sr deficiencies, with the final variety of the cores being consistent with an embedded TiOx rocksalt-like structure. I. INTRODUCTION
Grain boundaries have long been known to have farreaching effects on the bulk properties of perovskite materials. Notable examples include the reduction of the critical currents in high-temperature superconductors a)
Address all correspondence to this author. e-mail: [email protected] This paper was selected as an Outstanding Symposium Paper for the 2008 MRS Spring Meeting, Symposium Z. To maintain JMR’s rigorous, unbiased peer review standards, the JMR Principal Editor and reviewers were not made aware of the paper’s designation as Outstanding Symposium Paper. DOI: 10.1557/JMR.2009.0259 J. Mater. Res., Vol. 24, No. 7, Jul 2009
http://journals.cambridge.org
Downloaded: 03 Apr 2015
(YBa2Cu3O7),1,2 enhancement of the magneto-resistance effect in the manganates (La1-xCaxMnO3, SrCaMnO3, etc.),3,4 and increases in the dielectric constant in BaTiO3 and SrTiO3.5 For perovskites, the deviation of the grain boundary atomic structure with respect to the bulk typically induces a grain boundary potential, through which the bulk properties are influenced. Accurate calculations of the boundary potentials are extremely advantageous to current materials, and thus a clear understanding of the at
Data Loading...
