Effect of Cu²⁺ Ion Irradiation on Microstructure of Er₂O₃ Coating Layer Formed by MOCVD Method

Erbium oxide (Er₂O₃) coating is one of the promising methods to restrict tritium permeation and the magneto hydrodynamic pressure drop for advanced breeding blanket systems. Er₂O₃ coating layer on large interior surface area of metal pipe is deposited by using metal organic chemical vapor deposition process. In this work, the influence of Cu²⁺ ion irradiation on microstructure of Er₂O₃ coating layer on stainless steel 316 (SUS 316) substrate by metal organic chemical vapor deposition methods was investigated using scanning electron microscopy, transmission electron microscopy observation and X-ray diffraction analysis. Microstructure observation of Er₂O₃ coating was carried out after 0.00-1.50 dpa Cu²⁺ ion irradiation at 298 K and 773 K. Scanning electron microscopy observation of the surface area on Er₂O₃ thin film revealed the crack generation on surface after Cu²⁺ ion irradiation. X-ray diffraction peaks were identified in Er₂O₃ after Cu²⁺ ion irradiation transmission electron microscopy observations, the formation of interlayer between Er₂O₃ coating and SUS substrate was confirmed. According to transmission electron microscopy-energy dispersive spectroscopy, the interlayer includes Fe and Cr.