ARE NANOPHASE GRAIN-BOUNDARIES ANOMALOUS

The grain boundary regions of nanophase Cu metal are investigated usin g the x-ray absorption fine structure (XAFS) technique. Typical sample s made by standard techniques need to be greatly thinned if measured i n transmission in order to eliminate experimental artifacts which erro neously lower the apparent coordination number. To avoid this problem the samples were measured by the total electron yield technique. The r esults indicate a grain boundary structure which, on the average, is s imilar to that in conventional polycrystalline Cu, contrary to previou s XAFS measurements made in transmission which indicated a lower coord ination number.