摘要
非晶储氢材料有着优异的吸放氢能力,其微观结构与对应的合晶相之间存在着密切的联系,但目前无法在原子尺度上具体描述该种联系。引入并拓展了团簇加连接原子模型,提出双团簇模型即:C_(1){[主团簇]1(连接原子)1或3}+C_(2){[主团簇]2(连接原子)1或3},其中C_(1)、C_(2)满足杠杆定律,从团簇尺度上解释非晶材料与其对应合金相的结构遗传性。每个合金相可构建出多种团簇,需选取最能体现合金相结构的团簇作为主团簇。首先根据相对原子数密度准则选取密堆度最高的第一近邻配位多面体作为主团簇,然后根据杠杆定律计算深共晶成分两侧合金相的比例并构建双团簇式,最后选取成分最接近且价电子数符合八隅律定律的单团簇式组合作为储氢材料的双团簇式。利用该模型对Mg-Ni体系中储氢材料进行解析,解析值与实验结果吻合度高,研究揭示了深共晶成分与共晶相之间的相关性。
Amorphous hydrogen storage materials have excellent hydrogen absorption and release capabilities.Their microstructures are closely related to the corresponding crystalline phases,but it is not possible to describe this relationship at the atomic scale.In this paper,the cluster plus linked atom model is introduced and extended,and a dual-cluster model is proposed,namely C_(1){[principal cluster]1(glue atoms)1 or 3}+C_(2){[principal cluster]2(glue atoms)1 or 3},in which C_(1) and C_(2) conform to the lever law and explain the structural heritability of amorphous materials and their corresponding alloy phases at the cluster scale.Each alloy phase can construct multiple clusters,and the cluster that best reflects the alloy phase structure should be selected as the main cluster.Firstly,the first nearest neighbor coordination polyhedron with the highest density is selected as the principal cluster according to the relative atomic number density method,then the ratio of the alloy phases on both sides of the deep eutectic composition is calculated according to the lever law and the dual-cluster formula is constructed,and finally the single cluster combination with the closest composition to the experimental value and the valence electron number conforming to the law of 8n is selected as the dual-cluster formula of the hydrogen storage material.The model is used to analyze the hydrogen storage materials in the Mg-Ni system,and the results are in good agreement with the experimental results.The correlation between the deep eutectic composition and the eutectic phase is revealed,which provides a feasible method for the composition design of bulk metal glass.
作者
窦月辉
陈季香
李仕龙
许伯
王天宇
DOU Yuehui;CHEN Jixiang;LI Shilong;XU Bo;WANG Tianyu(School ofScience,Dalian Maritime University,Dalian 116026,China)
出处
《功能材料》
北大核心
2025年第5期5115-5119,共5页
Journal of Functional Materials
基金
中央高校基本科研业务费专项基金(3132014327)。
关键词
非晶储氢
双团簇式
密堆度
杠杆定律
价电子数
amorphous hydrogen storage
dual-clustered formulas
denseness
lever law
number of valence electrons
