Corrosion induced degradation of textured YBCO under operation in high humidity conditions

• Published in: Surface & coatings technology Vol. 206; no. 19-20; pp. 4256 - 4261
• Main Authors: Roa, J.J., Jiménez-Piqué, E., Díaz, J., Morales, M., Calleja, A., Segarra, M.
• Format: Journal Article Publication
• Language: English
• Published: Amsterdam Elsevier B.V 25-05-2012; Elsevier
• Subjects: Applied sciences; Atomic force microscopy; Bridgman method; Bridgman technique; COATINGS; COPPER OXIDE; CORROSION; Corrosion and anti-corrosives; Corrosion environments; Corrosió i anticorrosius; Cross-disciplinary physics: materials science; rheology; Degradation; EMBRITTLEMENT; Enginyeria dels materials; Exact sciences and technology; HUMIDITY; Materials science; MECHANICAL PROPERTIES; Metals. Metallurgy; Microscòpia de força atòmica; Nanoindentation; Nanotechnology; Nanotecnologia; PHASE TRANSFORMATIONS; Physics; SINGLE CRYSTALS; Superconductor; SUPERCONDUCTORS; Surface treatments; Transformations; YBCO superconductors; YTTRIUM OXIDE; Àrees temàtiques de la UPC; Superconductor; Atomic force microscopy; Bridgman technique; Corrosion; Nanoindentation; Humidity; Surface treatments; Indentation
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2012.04.035

The early stages of aggressive degradation at 85% of humidity for 24h of single crystals of YBa2Cu3O7−δ textured by Bridgman technique have been analyzed by means of atomic force microscopy, X-ray photoelectron spectroscopy, nanoindentation and focused ion beam. The results show that the initial formation of barium hydroxide and the non-superconducting green phase, Y2BaCuO5, induces the surface degradation and the loss of the mechanical properties as a consequence of the mechanical transformation after the degradation process due to an embrittlement of the superficial layer.
► We analyze the degradation and mechanical properties of YBCO samples. ► The nanoindentation technique acquired the hardness and elastic modulus. ► XPS, FIB and AFM helps to understand the degradation process. ► Results revealed that Y-211 phase is formed on the surface.