A class of high-mobility layered nanomaterials by design

Abstract

Design of materials with particular functional properties is indispensable albeit very challenging. Chemical and structural analogies can be helpful in this endeavor, especially when a particular combination of properties is sought after. Our aim is to bundle together 3 characteristics: high carrier mobility, magnetism, and scalability to nanomaterials in the form of a film – such a combination is particularly advantageous for spintronics. Here, inspired by recent studies of MAl2Si2 and related compounds, we develop magnetic EuAl2Ge2 and non-magnetic SrAl2Ge2 nanomaterials with high carrier mobility. Topotactic syntheses employing sacrificial 2D templates result in epitaxial films of MAl2Ge2 seamlessly integrated with germanium. The syntheses are followed by a study of the atomic structure, magnetic and electron transport properties. In particular, the films demonstrate high carrier mobility, exceeding 10,000 cm2 V–1 s–1 in the case of EuAl2Ge2, making the materials appealing for applications. Taken together, MAl2Ge2 and MAl2Si2 form a class of high-mobility layered nanomaterials.