Impact of symmetry on the ferroelectric properties of CaTiO3 thin films

Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He, Yayoi Takamura, Albina Borisevich, Long Qing Chen

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

Epitaxial strain is a powerful tool to induce functional properties such as ferroelectricity in thin films of materials that do not possess ferroelectricity in bulk form. In this work, a ferroelectric state was stabilized in thin films of the incipient ferroelectric, CaTiO3, through the careful control of the biaxial strain state and TiO6 octahedral rotations. Detailed structural characterization was carried out by synchrotron x-ray diffraction and scanning transmission electron microscopy. CaTiO3 films grown on La0.18Sr0.82Al0.59Ta0.41O3 (LSAT) and NdGaO3 (NGO) substrates experienced a 1.1% biaxial strain state but differed in their octahedral tilt structures. A suppression of the out-of-plane rotations of the TiO6 octahedral in films grown on LSAT substrates resulted in a robust ferroelectric I4?mm phase with remnant polarization ∼5?μC/cm2 at 10?K and Tc near 140?K. In contrast, films grown on NGO substrates with significant octahedral tilting showed reduced polarization and Tc. These results highlight the key role played by symmetry in controlling the ferroelectric properties of perovskite oxide thin films.

Original languageEnglish (US)
Article number162904
JournalApplied Physics Letters
Volume106
Issue number16
DOIs
StatePublished - Apr 20 2015

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Fingerprint

Dive into the research topics of 'Impact of symmetry on the ferroelectric properties of CaTiO<sub>3</sub> thin films'. Together they form a unique fingerprint.

Cite this