CHEMICAL INHOMOGENEITY AND REACTIONS OF BISRCACUO SURFACES DETECTED BY SYNCHROTRON IMAGING SPECTROMICROSCOPY

A microscopic chemical analysis of BiSrCaCuO (BSCCO) 2212 single cryst als was performed with an unprecedented combination of high (submicron ) lateral resolution and high energy resolution (100 meV or better). T he performances, achieved with imaging synchrotron spectromicroscopy, enabled us to detect in a very small fraction of the investigated spec imens, morphological and chemical inhomogeneities. Specifically, we fo und deviations from stoichiometry in the surface Sr content which have a subtle effect on the chemical environment of at least one other ele ment, Ca. The different chemical environment was found to influence su rface chemical reactions. (C) 1996 American Institute of Physics.