Picoscale materials engineering

Abstract

The way in which atoms bond to form a material — in particular the pattern of bond lengths and angles — is the fundamental determinant of the properties of the resulting material. Functional materials often derive their properties from alterable or reversible bond distortions at the picometre length scale that modify the electronic configuration. By considering several examples, we discuss how picoscale bond perturbations can be used to achieve specific materials properties. In particular, we examine the orbital engineering demonstrated in nickelates, the functional properties obtained in perovskite superlattices and the influence of interfacial effects on the high superconductive transition temperature of iron selenide. Moreover, we emphasize the relation between band topology and picoscale distortions in transition metal dichalcogenides and the effect of the excitation of lattice modes on materials properties. We use these examples to highlight how the combination of first-principles methods, materials growth techniques that allow control of the composition of individual atomic layers and state-of-the-art methods to characterize or dynamically excite picoscale bond distortions provides a powerful approach for discovering rules and concepts for picoscale materials engineering. Picoscale engineering of bonds is a powerful method to tune materials properties. Transcending nanoscience, picoscience offers the ultimate length scale to manipulate materials through subtle bond distortions between individual atoms, as this Review discusses through several examples ranging from perovskites to superconductors and to topological materials.