A Highly Strained Phase in PbZr0.2Ti0.8O3 Films with Enhanced Ferroelectric Properties. Issue 8 (18th February 2021)

• Record Type: Journal Article
• Authors: Huang, Chuanwei; Liao, Zhaolong; Li, Mingqiang; Guan, Changxin; Jin, Fei; Ye, Mao; Zeng, Xierong; Zhang, Tianjin; Chen, Zuhuang; Qi, Yajun; Gao, Peng; Chen, Lang
• Is Part Of: Advanced science. Volume 8:Issue 8(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-18
• Subjects: Curie temperature -- epitaxial ferroelectric films -- highly strained tetragonal phase -- negative thermal expansion; Science -- Periodicals; 505
• DOI: 10.1002/advs.202003582
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Although epitaxial strain imparted by lattice mismatch between a film and the underlying substrate has led to distinct structures and emergent functionalities, the discrete lattice parameters of limited substrates, combined with strain relaxations driven by film thickness, result in severe obstructions to subtly regulate electro‐elastic coupling properties in perovskite ferroelectric films. Here a practical and universal method to achieve highly strained phases with large tetragonal distortions in Pb‐based ferroelectric films through synergetic effects of moderately (≈1.0%) misfit strains and laser fluences during pulsed laser deposition process is demonstrated. The phase possesses unexpectedly large Poisson's ratio and negative thermal expansion, and concomitant enhancements of spontaneous polarization (≈100 µC cm −2 ) and Curie temperature (≈800 °C), 40% and 75% larger than that of bulk counterparts, respectively. This strategy efficiently circumvents the long‐standing issue of limited numbers of discrete substrates and enables continuous regulations of exploitable lattice states in functional oxide films with tightly elastic coupled performances beyond their present levels. Abstract : A highly distorted tetragonal phase with giant negative thermal expansions is achieved in Pb‐based ferroelectric films via synergistic effects of misfit strainand laser fluence, which possesses considerable enhancements of spontaneous polarization (≈100 µC cm −2 ) and Curie temperature (≈800 °C). This strategy efficiently circumvents the issue of limited substrates and enables continuous regulations of ferroelectric films with tightly elastic coupled functionality.