Proc. of the Yamada Conf. VII, Muon Spin Rotation, Shimoda, 1983 Hyperfine Interactions 17-19 (1984) 413-426 ELECTRONIC STRUCTURE AND MAGNETISM OF SURFACES, INTERFACES AND MODULATED STRUCTURES (SUPERLATTICES)* A.J. FREEMAN, T. JARLBORG*, H. KRAKAUER**, S. OHNISHI***, D.-S. WANG****, E. WIMMER*****, and M. WEINERT****** Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60201 U.S.A. Received 18 April 1983 Recent developments in the study of surfaces and interfaces of metals and of artificial materials such as bimetallic sandwiches and modulated structures are described. Key ques- tions include the effects on magnetism of reduced dimensionality and the possibility of magnetically "dead" layers. These developments have stimulated an intensified theoretical effort to investigate and describe the electronic and magnetic structure of surfaces and interfaces. One notable success has been the development of a highly accurate full-potential all-electron method (the FLAPW method) for solving the local spin density equations self- consistently for a single slab geometry. We describe here this advanced state of ab initio calculations in determining the magnetic properties of transition metal surfaces such as those of the ferromagnetic metals Ni(001) and Fe(001) and the Ni/Cu(001) interface. For both clean Fe and Ni(001) we find an enhancement of the magnetic moments in the surface layer. The magnetism of surface and interface Ni layers on Cu(001) (no "dead" layers are found) is described and compared to the clean Ni(001) results. Finally, the role ofpSR experiments in answering some of the questions raised in these studies will be discussed. 1. Introduction I have been asked to describe and discuss in this talk some recent advances in an important developing area in solid state physics/materials science. It has become clear in recent years that one of the most important developments in the last decade Department of Physics, University of Geneva, CH-1211 Geneva 4, Switzerland. Department of Physics, College of William and Mary, Williamsburg, VA 23185 U.S.A. NEC Corp., 1-1, Miyazaki 4-Chome, Miyamae-Ku, Kawasaki 213, Japan. Institute of Physics, Chinese Academy of Science, Beijing, China. Inst. F. Phys. Chem., Universit/it Wien, W~ihringerstr. 42, A-1090 Vienna, Austria. Department of Physics, Bldg. 510A, Brookhaven National Laboratory, Upton, NY 11973 U.S.A. 9 J.C. Baltzer AG, Scientific Publishing Company, and Yamada Science Foundation