Global Young Investigator Awardee 2023

Dr. Chenxu Wang is an Assistant Professor in the School of Physics at the Peking University, China. He received his BS in Applied Physics from Jilin University in 2011, and his Ph.D. in Nuclear Technology and Application from Peking University in 2016. Dr. Wang worked at Stanford University as a postdoctoral researcher from 2016 to 2020. He has published 50 peer-reviewed papers and received the Excellent Graduates Award, Excellent Ph.D. Dissertation Award and the Best Oral presentation Award at the CICC. Dr. Wang’s research interests are in materials in extreme environments, including radiation effects in novel nuclear materials, H/He synergistic effect in fusion reactors, and material modification using ion beams and high pressure.

Title: MAX phases in extreme environments

Abstract:  Mn+1AXn phases exhibit unique laminated atomic structures that result in properties typical of both ceramics and metals. Due to their unusual characteristics, these materials have been proposed for use in a wide variety of industrial applications, including in nuclear systems where they will be exposed to severe irradiation conditions, high temperatures, and high pressure. In this talk, I will summarize recent experimental and theoretical work on the behaviors of the Mn+1AXn phases in these extreme environments. I will present the direct observation of irradiation-induced antisite defects in Mn+1AXn phases and chemical disordering at the atomic scale using high-resolution (HR) aberration-corrected STEM HAADF and ABF imaging. An order-to-disorder, hex-to-γ-to-fcc phase transformation and the formation of metastable solid solution phases were observed using synchrotron grazing incidence X-ray diffraction (GIXRD), atom probe tomography (APT), and first-principle calculations. The role of elemental composition and chemical complexity at cation sites in the radiation tolerance of Mn+1AXn phases will be discussed. This talk will provide a comprehensive understanding of the mechanisms of structural modification and defect evolution in Mn+1AXn phases, as well as proposed strategies for designing novel Mn+1AXn phases with enhanced performance under extreme irradiation conditions.

 

Share/Print