Oxide Materials at the Two-Dimensional Limit Preface

The study of two-dimensional materials, i.e. materials consisting of mono-atomic or few-atom-thick layers, is at the forefront of present-day solid state physics and chemistry. Indeed, prompted by the discovery of graphene and graphene-like materials, a veritable hype of scientific activity has set in in this field of low-dimensional systems, as documented by the exponential growth of published article numbers (for a recent review on materials beyond graphene, see e.g. S.Z. Butler at al., "Progress, challenges, and opportunities in two-dimensional materials beyond graphene", ACS Nano 7 (2013) 2898). In the field of metal oxides, ultrathin films of oxides are a theme of actual interest, whereby a trend towards decreasing thickness of oxide films can be noted, eventually reaching the ultimate limit of single-atom or single-polyhedral-thick layers. These oxide systems at the two-dimensional limit are in use at present mostly as model systems in studies of their novel emergent properties, but there are potential applications in view in diverse areas of chemistry and physics, for example as novel types of monolayer catalysts or as elements in electronic nanodevice technologies. When asked by Springer Science Publishers to edit a book on "Oxide Materials at the Two-dimensional Limit", we thought therefore that it is a timely project to undertake this challenge.