@article{0a37c7ed794d4d4e9a73f900957d4884,
title = "Real space imaging of the microscopic origins of the ultrahigh dielectric constant in polycrystalline Ca Cu3 Ti4 O12",
abstract = "The origins of an ultrahigh dielectric constant in polycrystalline Ca Cu3 Ti4 O12 (CCTO) were studied using the combination of impedance spectroscopy, electron microscopy, and scanning probe microscopy (SPM). Impedance spectra indicate that the transport properties in the 0.1 Hz-1 MHz frequency range are dominated by a single parallel resistive-capacitive (RC) element with a characteristic relaxation frequency of 16 Hz. dc potential distributions measurements by SPM illustrate that significant potential drops occur at the grain boundaries, which thus can be unambiguously identified as the dominant RC element. High frequency ac amplitude and phase distributions illustrate very weak grain boundary contrast in SPM, indicative of strong capacitive coupling across the interfaces. These results demonstrate that the ultrahigh dielectric constant reported for polycrystalline CCTO materials is related to grain-boundary behavior.",
author = "Kalinin, {S. V.} and J. Shin and Veith, {G. M.} and Baddorf, {A. P.} and Lobanov, {M. V.} and H. Runge and M. Greenblatt",
note = "Funding Information: Research was performed as a Eugene P. Wigner Fellow and staff member at the Oak Ridge National Laboratory (ORNL), and managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725 for one of the authors (S.V.K.). Support from ORNL Laboratory Research and Development funding is acknowledged by two of the authors (S.V.K. and A.P.B.). Another author (G.M.V.) was supported in part by an appointment to the ORNL Postdoctoral Research Associates Program administered jointly by the Oak Ridge Institute for Science and Education and ORNL. The work at Rutgers was supported by NSF Grant Nos. DMR 99-07963 and DMR 02-33697. Research carried out at the NSLS at Brookhaven National Laboratory was supported by the U.S. Department of Energy, Division of Materials Sciences and Division of Chemical Sciences. The SUNY X3 beamline at NSLS was supported by the Division of Basic Energy Sciences of the U.S. Department of Energy under Grant No. DE-FG02-86ER45231. The authors are grateful to C. Botez and P. W. Stephens for the help with SXD data collection, and G. Ownby, J. Luck, and Dr. P. Khalifah (ORNL) for invaluable help in sample preparation.",
year = "2005",
month = mar,
day = "7",
doi = "10.1063/1.1880432",
language = "English (US)",
volume = "86",
pages = "1--3",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "10",
}