A study was made of microcrystals which had been aged under ambient conditions for 960h. Combined X-ray absorption near-edge structure and X-ray fluorescence measurements with μm spatial resolution revealed an increase in Cu+ with respect to Cu2+, and an enrichment of the Cu versus Bi and Sr cation content near to the sample edges in the b-axis direction. A parallel study of an electrically contacted sample indirectly detected the O loss; detecting both a resistivity increase and an increase in sample thickness near to the edges. It was concluded that the O out-diffusion along the b-axis was accompanied by Cu-cation migration in the same direction.

Evidence of Ion Diffusion at Room Temperature in Microcrystals of the Bi2Sr2CaCu2O8+δ Superconductor. M.Truccato, C.Lamberti, C.Prestipino, A.Agostino: Applied Physics Letters, 2005, 86[21], 213116 (3pp)