Huang Gui-Yang, Hu Xunxiang, Wirth Brian D
Department of Nuclear Engineering, University of Tennessee, knoxville, Tennessee, United States of America.
J Phys Condens Matter. 2020 Nov 25;32(49):495001. doi: 10.1088/1361-648X/abb17e.
Based on first-principles calculations, the binding energy of hydrogen atom to YO and YO|bcc Fe interface (relative to bcc Fe side) with cube-on-cube orientation is at least 0.45 eV, if hydrogen substitutional is considered, or at least 0.26 eV if only hydrogen interstitial is considered. The calculated binding energies do not have a unique fixed value, because they are dependent on the interface structure, the Fermi level of YO near the interface and the chemical potential of Y/O. Hydrogen substitutional is more stable than hydrogen interstitial near the interface for Fermi level around calculated Schottky barrier height (SBH) at equilibrium. The YO particle interior can be an effective trapping site for hydrogen. Hydrogen interstitial, hydrogen substitutional and Y/O vacancy have a much lower energy near the interface than within the YO particle, presumably due to image charge interaction related to their non-zero charge state. For neutral impurities or defects, the energy near interface and that far away from the interface are similar (⩽0.1 eV difference) for a perfect coherent interface. The YO|bcc Fe interface should provide effective trapping sites for hydrogen atoms in oxide dispersion strengthened (ODS) steels.
基于第一性原理计算，如果考虑氢的取代，氢原子与具有立方取向的YO和YO|bcc Fe界面（相对于bcc Fe一侧）的结合能至少为0.45 eV；如果仅考虑氢的间隙态，则至少为0.26 eV。计算得到的结合能没有唯一的固定值，因为它们取决于界面结构、界面附近YO的费米能级以及Y/O的化学势。在平衡态下，对于接近计算得到的肖特基势垒高度（SBH）的费米能级，界面附近的氢取代比氢间隙态更稳定。YO颗粒内部可以成为氢的有效俘获位点。氢间隙态、氢取代态和Y/O空位在界面附近的能量比在YO颗粒内部低得多，这可能是由于与它们非零电荷态相关的镜像电荷相互作用。对于中性杂质或缺陷，对于完美相干界面，界面附近和远离界面的能量相似（差值⩽0.1 eV）。YO|bcc Fe界面应该为氧化物弥散强化（ODS）钢中的氢原子提供有效的俘获位点。
