Strain Effect in Epitaxial Oxide Heterostructures

Abstract

In recent decades, extensive studies have been conducted on controlling and engineering novel functionalities in transition metal oxide (TMO) heterostructures by epitaxial strain. In this chapter, we discuss popular transition metal oxide thin films in the context of various research fields that are extensively studied in condensed matter physics. These materials include La 1.85 Sr 0.15 CuO 4 (a high temperature superconductor), SrRuO 3 (a highly conductive ferromagnetic metal), La 0.67 Sr 0.33 MnO 3 (a colossal magnetoresistive ferromagnetic metal), BiFeO 3 (a multiferroic oxide), LaAlO 3 -SrTiO 3 (a conductive oxide interface), and LaNiO 3 (a strongly correlated metal). We focus on the appearance of novel functional properties from imposing epitaxial strain (compressive or tensile strain caused by the use of various lattice-mismatched substrates) on these films that cannot be observed in their bulk form. Subsequently, the intrinsic mechanisms for these novel phenomena are discussed based on experimental observations and theoretical modelling. We conclude that by using epitaxial strain, not only can thin film functionalities be tuned but many novel correlated phenomena can also be created. We believe that our collective efforts on the strain engineering of various transition metal oxide thin films will provide an insightful description of this emerging subject from a fundamental physics and nanoscale device applications point of view.

Novel composite color converters based on Tb1.5Gd1.5Al5O12:Ce single crystalline films and Y3Al5O12:Ce crystal substrates

“…33 As a rule, compressive strain is induced in a film when a film > a substrate , which is compressed along the in-plane direction. 34 The quantitative amount of strain ( ε ) induced in a film is described as follows.…”

High Yield Transfer of Clean Large-Area Epitaxial Oxide Thin Films

“…Figure 4c, d shows magnified images of the film, revealing no macroscopic cracking. The resistivity (ρ) is only slightly increased from 203 to 223 μΩ cm (9.9%) at 297 K. This may be explained by the release of − 0.46% inplane compressive strain in the film, as SrRuO 3 is reported to have lower resistivity when compressively strained [53,54]. However, small random cracks might also contribute to the marginally higher resistivity.…”

Insights into Strain Engineering: From Ferroelectrics to Related Functional Materials and Beyond

“…With recent advancements in thin-film fabrication techniques, epitaxial growth has evolved from monophase epitaxy to multiphase deposition. 29 configurations and interfacial structures, such as 0−3, 1−3, and 2−3 types (the number denotes the characteristic dimensions), appear in composite films according to the arrangement and connectivity of each phase 196,197 (Figure 15a,b). Interphase strain engineering has recently emerged as a strategy for controlling lattice strains in composite systems.…”