An experimental study of copper self-diffusion in CuO, Y2Cu2O5 and YBa2Cu3O7–x by secondary neutral mass spectrometry

Abstract

Copper self-diffusion has been studied in CuO, Y₂Cu₂O₅ and YBa₂Cu₃O_7–xceramics by the SNMS (secondary neutral mass spectrometry) technique in the temperature range 700–900 °C with the stable isotope⁶³Cu used as a tracer. The lowest diffusion rate and the highest value of activation energy were found for the Y₂Cu₂O₅ phase. Copper self-diffusion was also studied along the c axis of YBa₂Cu₃O_7–xsingle crystals. It was shown that the anisotropy of Cu diffusion in YBa₂Cu₃O_7–xis rather high. The diffusion rate in thec direction of single crystals is more than two orders of magnitude lower than that in ceramic samples.