PREPARATION OF OXIDE SUPERCONDUCTOR SPECIMENS FOR TEM EXAMINATION

We have investigated a wide variety of oxide superconductors and repor t here on a number of techniques that can be effectively used to prepa re transmission electron microscopy (TEM) specimens from these materia ls. Crushing, cleaving, ion milling, ultramicrotomy, and jet polishing all were successfully utilized, and details of each technique, as wel l as equipment used, are described. Selection among these methods depe nds both on the starting form of the material and the information requ ired. Ion milling and crushing generally give the best results and hav e the widest applicability in our particular work, while crushing and cleaving involve the least equipment cost. In some cases, particularly with ion milling and jet polishing, small variations in the details o f preparation have a dramatic effect on the success rate. We have foun d it to be a great advantage that the same techniques can be applied i n a similar manner to a whole range of oxide materials, even (with som e refinements and special precautions) to those that are extremely oxy gen or moisture sensitive. (C) 1995 Wiley-Liss, Inc.