Octahedral tilts are the most ubiquitous distortions in perovskite-related structures that can dramatically influence ferroelectric, magnetic, and electronic properties; yet the paradigm of tilt epitaxy in thin films is barely explored. Non-destructively characterizing such epitaxy in three-dimensions for low symmetry complex tilt systems composed of light anions is a formidable challenge. Here we demonstrate that the interfacial tilt epitaxy can transform ultrathin calcium titanate, a non-polar earth-abundant mineral, into high-temperature polar oxides that last above 900 K. The comprehensive picture of octahedral tilts and polar distortions is revealed by reconstructing the three-dimensional electron density maps across film-substrate interfaces with atomic resolution using coherent Bragg rod analysis. The results are complemented with aberration-corrected transmission electron microscopy, film superstructure reflections, and are in excellent agreement with density functional theory. The study could serve as a broader template for non-destructive, three-dimensional atomic resolution probing of complex low symmetry functional interfaces.
%0 Journal Article
%1 yuan2018threedimensional
%A Yuan, Yakun
%A Lu, Yanfu
%A Stone, Greg
%A Wang, Ke
%A Brooks, Charles M.
%A Schlom, Darrell G.
%A Sinnott, Susan B.
%A Zhou, Hua
%A Gopalan, Venkatraman
%D 2018
%J Nature Communications
%K atomic density electron scale
%N 1
%P 5220--
%R 10.1038/s41467-018-07665-1
%T Three-dimensional atomic scale electron density reconstruction of octahedral tilt epitaxy in functional perovskites
%U https://doi.org/10.1038/s41467-018-07665-1
%V 9
%X Octahedral tilts are the most ubiquitous distortions in perovskite-related structures that can dramatically influence ferroelectric, magnetic, and electronic properties; yet the paradigm of tilt epitaxy in thin films is barely explored. Non-destructively characterizing such epitaxy in three-dimensions for low symmetry complex tilt systems composed of light anions is a formidable challenge. Here we demonstrate that the interfacial tilt epitaxy can transform ultrathin calcium titanate, a non-polar earth-abundant mineral, into high-temperature polar oxides that last above 900 K. The comprehensive picture of octahedral tilts and polar distortions is revealed by reconstructing the three-dimensional electron density maps across film-substrate interfaces with atomic resolution using coherent Bragg rod analysis. The results are complemented with aberration-corrected transmission electron microscopy, film superstructure reflections, and are in excellent agreement with density functional theory. The study could serve as a broader template for non-destructive, three-dimensional atomic resolution probing of complex low symmetry functional interfaces.
@article{yuan2018threedimensional,
abstract = {Octahedral tilts are the most ubiquitous distortions in perovskite-related structures that can dramatically influence ferroelectric, magnetic, and electronic properties; yet the paradigm of tilt epitaxy in thin films is barely explored. Non-destructively characterizing such epitaxy in three-dimensions for low symmetry complex tilt systems composed of light anions is a formidable challenge. Here we demonstrate that the interfacial tilt epitaxy can transform ultrathin calcium titanate, a non-polar earth-abundant mineral, into high-temperature polar oxides that last above 900 K. The comprehensive picture of octahedral tilts and polar distortions is revealed by reconstructing the three-dimensional electron density maps across film-substrate interfaces with atomic resolution using coherent Bragg rod analysis. The results are complemented with aberration-corrected transmission electron microscopy, film superstructure reflections, and are in excellent agreement with density functional theory. The study could serve as a broader template for non-destructive, three-dimensional atomic resolution probing of complex low symmetry functional interfaces.},
added-at = {2018-12-13T14:39:48.000+0100},
author = {Yuan, Yakun and Lu, Yanfu and Stone, Greg and Wang, Ke and Brooks, Charles M. and Schlom, Darrell G. and Sinnott, Susan B. and Zhou, Hua and Gopalan, Venkatraman},
biburl = {https://www.bibsonomy.org/bibtex/2c1c7a4eb79f6f0d9234ae8c1efe46158/sere},
doi = {10.1038/s41467-018-07665-1},
interhash = {5333a376ab3ce88e277948c65300f690},
intrahash = {c1c7a4eb79f6f0d9234ae8c1efe46158},
issn = {20411723},
journal = {Nature Communications},
keywords = {atomic density electron scale},
number = 1,
pages = {5220--},
refid = {Yuan2018},
timestamp = {2018-12-13T14:39:48.000+0100},
title = {Three-dimensional atomic scale electron density reconstruction of octahedral tilt epitaxy in functional perovskites},
url = {https://doi.org/10.1038/s41467-018-07665-1},
volume = 9,
year = 2018
}