Effects of Monovacancy and Divacancies on Hydrogen Solubility, Trapping and Diffusion Behaviors in fcc-Pd by First Principles

• Published in: Materials Vol. 13; no. 21; p. 4876
• Main Authors: Ma, Bao-Long, Wu, Yi-Yuan, Guo, Yan-Hui, Yin, Wen, Zhan, Qin, Yang, Hong-Guang, Wang, Sheng, Wang, Bao-Tian
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30-10-2020; MDPI
• Subjects: Behavior; Blistering; Clustering; Composite materials; Defects; diffusion barrier; Divacancies; Energy; First principles; H solution energy; Hydrogen; hydrogen bubble; Impurities; Mathematical analysis; Metals; Point defects; Radiation tolerance; Trap efficiency; Vacancies
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma13214876

The hydrogen blistering phenomenon is one of the key issues for the target station of the accelerator-based neutron source. In the present study, the effect of monovacancies and divacancies defects on the solution, clustering and diffusion behaviors of H impurity in fcc-Pd were studied through first principles calculations. Our calculations prove that vacancies behave as an effective sink for H impurities. We found that, although the H-trap efficiency of the larger vacancy defect was reduced, its H-trap ability strengthened. There is a short-ranged area around the vacancy defects in which H impurities tend to diffuse to vacancy defects, gather and form hydrogen bubbles. Therefore, the characteristic of large vacancy defects formation in materials should be considered when screening anti-blistering materials for neutron-producing targets or when designing radiation resistant composite materials.