title: Defective interfaces in yttrium-doped barium zirconate films and consequences on proton conduction.
abstract: Yttrium-doped barium zirconate (BZY) thin films recently showed surprising electric transport properties. Experimental investigations conducted mainly by electrochemical impedance spectroscopy suggested that a consistent part of this BZY conductivity is of protonic nature. These results have stimulated further investigations by local unconventional techniques. Here, we use electrochemical strain microscopy (ESM) to detect electrochemical activity in BZY films with nanoscale resolution. ESM in a novel cross-sectional measuring setup allows the direct visualization of the interfacial activity. The local electrochemical investigation is compared with the structural studies performed by state of art scanning transmission electron microscopy (STEM). The ESM and STEM results show a clear correlation between the conductivity and the interface structural defects. We propose a physical model based on a misfit dislocation network that introduces a novel 2D transport phenomenon, whose fingerprint is the low activation energy measured.
authors: †National Research Council CNR-SPIN, University of Roma "Tor Vergata", Rome I-00133, Italy.|‡NAST Center, University of Roma "Tor Vergata", Rome I-00133, Italy.|§Engineering Faculty, Università degli studi Niccolò Cusano, Rome I-00166, Italy.
authors: Nan
authors: N
authors: Yang
authors: ∥Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors: Claudia
authors: C
authors: Cantoni
authors: †National Research Council CNR-SPIN, University of Roma "Tor Vergata", Rome I-00133, Italy.|⊥Department DICII, University of Roma Tor Vergata, Rome I-00133, Italy.
authors: Vittorio
authors: V
authors: Foglietti
authors: †National Research Council CNR-SPIN, University of Roma "Tor Vergata", Rome I-00133, Italy.|‡NAST Center, University of Roma "Tor Vergata", Rome I-00133, Italy.|⊥Department DICII, University of Roma Tor Vergata, Rome I-00133, Italy.
authors: Antonello
authors: A
authors: Tebano
authors: ∇Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors: Alex
authors: A
authors: Belianinov
authors: ∇Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors: Evgheni
authors: E
authors: Strelcov
authors: ∇Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors: Stephen
authors: S
authors: Jesse
authors: †National Research Council CNR-SPIN, University of Roma "Tor Vergata", Rome I-00133, Italy.|⊥Department DICII, University of Roma Tor Vergata, Rome I-00133, Italy.
authors: Daniele
authors: D
authors: Di Castro
authors: ‡NAST Center, University of Roma "Tor Vergata", Rome I-00133, Italy.|¶Department of Chemical Sciences and Technologies, University of Roma "Tor Vergata", Rome 00133, Italy.
authors: Elisabetta
authors: E
authors: Di Bartolomeo
authors: ‡NAST Center, University of Roma "Tor Vergata", Rome I-00133, Italy.|¶Department of Chemical Sciences and Technologies, University of Roma "Tor Vergata", Rome 00133, Italy.
authors: Silvia
authors: S
authors: Licoccia
authors: ∇Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors: Sergei V
authors: SV
authors: Kalinin
authors: †National Research Council CNR-SPIN, University of Roma "Tor Vergata", Rome I-00133, Italy.|⊥Department DICII, University of Roma Tor Vergata, Rome I-00133, Italy.
authors: Giuseppe
authors: G
authors: Balestrino
authors: †National Research Council CNR-SPIN, University of Roma "Tor Vergata", Rome I-00133, Italy.|‡NAST Center, University of Roma "Tor Vergata", Rome I-00133, Italy.|⊥Department DICII, University of Roma Tor Vergata, Rome I-00133, Italy.
authors: Carmela
authors: C
authors: Aruta
keywords: SPM; STEM; doped barium zirconate; electrolytes; interface defects; ionic conduction; perovskite oxide thin films