Induced ferroelectric phases in SrTiO3 by a nanocomposite approach

Authors

Erik Enriquez, The University of Texas Rio Grande Valley
Qian Li
Pamela Bowlan
Ping Lu
Bruce Zhang
Leigang Li
Haiyan Wang
Antoinette J. Taylor
Dmitry Yarotski
Rohit P. Prasankumar

Document Type

Article

Publication Date

8-21-2020

Abstract

Inducing new phases in thick films via vertical lattice strain is one of the critical advantages of vertically aligned nanocomposites (VANs). In SrTiO3 (STO), the ground state is ferroelastic, and the ferroelectricity in STO is suppressed by the orthorhombic transition. Here, we explore whether vertical lattice strain in three-dimensional VANs can be used to induce new ferroelectric phases in SrTiO3:MgO (STO:MgO) VAN thin films. The STO:MgO system incorporates ordered, vertically aligned MgO nanopillars into a STO film matrix. Strong lattice coupling between STO and MgO imposes a large lattice strain in the STO film. We have investigated ferroelectricity in the STO phase, existing up to room temperature, using piezoresponse force microscopy, phase field simulation and second harmonic generation. We also serendipitously discovered the formation of metastable TiO nanocores in MgO nanopillars embedded in the STO film matrix. Our results emphasize the design of new phases via vertical epitaxial strain in VAN thin films.

Comments

Original published version available at https://doi.org/10.1039/D0NR03460F

Recommended Citation

Nanoscale, 2020,12, 18193-18199. DOI https://doi.org/10.1039/D0NR03460F

Publication Title

Nanoscale

DOI

10.1039/D0NR03460F