Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture (Angew. Chem. Int. Ed. Engl. 5/1988)
The cover shows a high-resolution lattice image of a 2.8nm-GaAs/2.3nm AlAs superlattice. The perfect ordering of the lattice units clearly continues beyond the interfaces. In semiconductor superlattices an artificial periodicity is imposed on a crystal which leads to the formation of mini- or sub-bands for electrons and for holes and thereby gives rise to novel electrical and optical properties. Such multilayer heterostructures with atomically abrupt material transitions can be produced by molecular beam epitaxy. How this process of “spatially resolved materials synthesis” functions, what it can be used for, and how the products are characterized, are outlined by K. Ploog in a review on p. 593 ff.ADVANCED MATERIALS is the title of a new, independent section of ANGEWANDTE CHEMIE which appears for the first time in this issue. This section will again appear in the July issue of the journal and, thereafter, monthly from September onwards. That a new independent section can find place under the covers of this journal has tradition, and, if tradition is followed, ADVANCED MATERIALS, like its predecessor “Nachrichten aus Chemie, Technik und Laboratorium”, which was an independent section of ANGEWANDTE CHEMIE up to 1976, may also eventually develop into being a completely independent journal. The decision to include this section in the journal will not fall to the detriment of the Reviews and Communications sections; these sections will remain unaltered—only a steady growth is envisaged.-- Some kind of cooperation between experts from various disciplines has always been essential for the development of new materials; in many cases it now requires more interdisciplinary cooperation. A chemist who wants to design and synthesize compounds for application in non-linear optics must at least understand the relevant fundamental physics and must also think about the processing of the new materials. A physicist interested in high-temperature superconductors must be conversant with the fundamentals of structural chemistry and he will also be interested in the applications of these “ceramics”. Materials scientists, physicists and chemists are coming closer together—ADVANCED MATERIALS will serve as a medium for promoting interdisciplinary discussion. Further details of the envisaged program are given in the Editorial on p. 723.