Cerium oxide inclusion nucleation mechanism based on classical nucleation theory and two-step nucleation  

作　　者：Yutang Li Jun Wang Linzhu Wang Chaoyi Chen Shufeng Yang Junqi Li Xiang Li 

机构地区：[1]School of Materials and Metallurgy,Guizhou University,Guiyang,550025,China [2]State Key Laboratory of Public Big Data,Guizhou University,Guiyang,550025,China [3]School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing,100083,China [4]Department of Materials&Metallurgy Engineering,Guizhou Institute of Technology,Guiyang,550003,China

出　　处：《Journal of Rare Earths》2024年第4期793-802,共10页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(52064011,52274331);Science and Technology Planning Project of Guizhou(Qian Ke He Ji Chu ZK[2021]258,Qian Ke He Chengguo[2022]089,Qian Ke He Chengguo[2021]086)。

摘　　要：It is challenging to assess the mechanism responsible for the nucleation of inclusions in metals at high temperatures.The present work therefore systematically investigates the nucleation of cerium oxide inclusions according to classical nucleation theory and a two-step nucleation mechanism.The nucleation rates and nucleation radii of these inclusions are obtained,and the results demonstrate a considerable difference between theoretical and experimental values.On the basis of a two-step nucleation mechanism,(CeO_(2))_(n) and(Ce_(2)O_(3))_(n)(n=1-6)clusters were constructed and the thermodynamic properties of both these clusters and of cerium oxide nanoparticles were analyzed.In addition,the entropies and heat capacity changes of cerium oxides were determined using first principles calculations and are found to be consistent with literature data.The present data indicate that the cerium oxide inclusion nucleation pathway can be summarized as[Ce]+[O]→(CeO_(2))n/(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(2)→core(Ce_(2)O_(3)crystal)-shell((Ce_(2)O_(3))_(2) cluster)nanoparticles→(Ce_(2)O_(3))bulk.

关 键 词：Cerium oxide inclusion Classical nucleation theory Two-step nucleation mechanism First principles Rare earths 

分 类 号：TG142.1[一般工业技术—材料科学与工程]