MAGNETICALLY DRIVEN BUCKLING AND STABILITY OF ORDERED SURFACE ALLOYS - CU(100)C(2 X 2)MN

We present evidence for a new class of magnetic materials, namely two-dimensional, ordered surface alloys. Structure and composition of the prototype Cu(100)c(2 x 2)Mn were determined by a quantitative low energy electron diffraction analysis, which shows an unusually large buckling in the surface alloy layer. By comparing our results with ab initio total energy calculations we identified the magnetism of Mn as the driving force for the buckling and moreover for the stability of the alloy. Possible additional members of this new class of materials are suggested.