@article{2a080735ebcb4dc2b1edbb719c7f1877,
title = "Improper Inversion Symmetry Breaking and Piezoelectricity through Oxygen Octahedral Rotations in Layered Perovskite Family, LiRTiO4 (R = Rare Earths)",
abstract = "An improper mechanism for breaking inversion symmetry is revealed and thus inducing piezoelectricity in the family of layered perovskites, LiRTiO4 (R = rare earths), which are previously reported as centrosymmetric. Noncentrosymmetry in this family of compounds arises from TiO6 octahedral rotation represented by a−boco/boa−co in the perovskite blocks between RO rock salt and LiO antifluorite layers. X-ray diffraction and optical second harmonic generation complemented by density functional theory predictions are crucial in determining the new structures. High transition temperature (Tac) of up to 1200 K from noncentrosymmetric to centrosymmetric phase is observed. Piezoelectric coefficients (d36) of up to −15 pC/N are predicted, and piezoelectric force microscopy experiments confirm a piezoelectric response. The demonstrated improper mechanism in this and other layered oxide families, with a wide range of available topologies and chemistries, could aid in the search for high temperature piezoelectrics.",
author = "Gupta, {Arnab Sen} and Hirofumi Akamatsu and Strayer, {Megan E.} and Shiming Lei and Toshihiro Kuge and Koji Fujita and {dela Cruz}, Clarina and Atsushi Togo and Isao Tanaka and Katsuhisa Tanaka and Mallouk, {Thomas E.} and Venkatraman Gopalan",
note = "Funding Information: This work was primarily supported by the National Science Foundation under MRSEC grant DMR-1420620. S. L. and V. G. were also partially supported by DMR-1210588. The authors thank Dr. James Rondinelli for helpful discussions about this project. The research conducted at ORNL's High Flux Isotope Reactor was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. H.A. would like to acknowledge support from Japan Society for the Promotion of Science for Research Abroad (No. 25-185). M.E.S. would like to acknowledge the National Science Foundation Graduate Fellowship grant DGE-1255832. K.F. would like to acknowledge Japan Synchrotron Radiation Research Institute (Proposal No. 2015A1151) for SXRD measurements and JSPS KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas “Nano Informatics” (Grant No. 26106514). Publisher Copyright: {\textcopyright} 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim",
year = "2016",
month = jan,
day = "1",
doi = "10.1002/aelm.201500196",
language = "English (US)",
volume = "2",
journal = "Advanced Electronic Materials",
issn = "2199-160X",
publisher = "Wiley-VCH Verlag",
number = "1",
}