Atomic-level insights into the initial oxidation mechanism of high-entropy diborides by first-principles calculations  

作　　者：Yiwen Liu Hulei Yu Hong Meng Yanhui Chu 

机构地区：[1]School of Materials Science and Engineering,South China University of Technology,Guangzhou,510641,China

出　　处：《Journal of Materiomics》2024年第2期423-430,共8页无机材料学学报（英文）

基　　金：support from the National Key Research and Development Program of China(No.2021YFA0715801);the National Natural Science Foundation of China(Nos.52122204 and 51972116);Guangzhou Basic and Applied Basic Research Foundation(No.202201010632).

摘　　要：Understanding the initial oxidation mechanism is critical for studying the oxidation resistance of high-entropy diborides.However,related studies are scarce.Herein,the initial oxidation mechanism of(Zr_(0.25)Ti_(0.25)Nb_(0.25)Ta_(0.25))B_(2)high-entropy diborides(HEB_(2)-1)is investigated by first-principles calculations at the atomic level.By employing the two-region model method,the most stable surface of HEB_(2)-1 is determined to be(1120)surface.The dissociative adsorption process of the oxygen molecule on the HEB_(2)-1-(1120)surface is predicted to proceed spontaneously,where OeO bond breaks and each oxygen atom is chemisorbed on the most preferable hollow site.The adsorption energy and the diffusion barrier of the oxygen atom on the(1120)surface of HEB_(2)-1 are in the vicinity of the average level of the cor-responding four individual diborides.In addition,ab initio molecular dynamics simulations indicate a high initial oxidation resistance of HEB_(2)-1 at 1000 K.Our results are beneficial to further designing the high-entropy diborides with excellent oxidation resistance.

关 键 词：High-entropy diborides Oxidation First-principles calculations 

分 类 号：O64[理学—物理化学]