材料科学
热膨胀
铁电性
薄膜
基质(水族馆)
钙钛矿(结构)
凝聚态物理
密度泛函理论
格子(音乐)
外延
热的
晶格常数
热力学
纳米技术
复合材料
光电子学
衍射
结晶学
光学
物理
电介质
量子力学
化学
地质学
声学
图层(电子)
海洋学
作者
Ethan T. Ritz,Nicole A. Benedek
出处
期刊:Physical Review Materials
[American Physical Society]
日期:2020-08-25
卷期号:4 (8)
被引量:5
标识
DOI:10.1103/physrevmaterials.4.084410
摘要
The sensitivity of materials properties, particularly those of perovskite oxides, to epitaxial strain has been exploited to great advantage to create materials with new or enhanced properties. Although it has certainly been recognized that mismatch in the thermal expansion coefficients of the bulk and substrate material will contribute to the misfit strain, the significance of this contribution for ferroelectric perovskite thin-films has not been systematically explored. We use first-principles density functional theory and the example of ferroelectric PbTiO$_3$ thin-films on various substrates to show that ignoring the thermal expansion of the substrate (that is, assuming that the in-plane lattice parameter of the film remains roughly constant as a function of temperature) results in ferroelectric transition temperatures and structural trends that are completely qualitatively different from calculations in which thermal expansion mismatch is properly taken into account. Our work suggests that the concept of a misfit strain defined as a single number is particularly ill-defined for PbTiO$_3$ and invites further study of the interplay between thermal expansion mismatch and structural and functional properties in other thin-film materials.
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