摘要
采用分子动力学方法和Quantum Sutton-Chen多体势,对液态金属Cu的快速凝固过程进行了计算机模拟跟踪研究。运用Honeycutt-Andersen(HA)键型指数法和原子成团类型指数法(CTIM)分析了金属Cu原子的成键类型和形成的原子团簇结构。研究发现,系统形成以1551、1541和14313种键型为主的非晶态结构;二十面体原子团(120120)和缺陷多面体基本原子团(12282)、(131102)、(13364)、(141103)、(14284)、(14365)在液态转变为非晶体过程中起到了关键性作用;系统所形成的纳米级团簇由一些基本多面体原子团相互连接而成,这正是与由气相沉积法和离子溅射法所获得的团簇结构的本质差别。通过对双体分布函数g(r)、HA键型、基本原子团和平均原子体积的分析,还得到液态金属Cu在冷却速率为1.0×1014K/s时的非晶转变温度Tg约为673K。
A computer simulation tracking study for the rapid solidification processes of liquid metal Cu system is performed by means of molecular dynamics method and the quantum Sutto-Chen many-body potential. Using the in- dex method of Honeycutt-Andersen（HA）and the cluster-type index method （CTIM）,the bond-types and cluster con- figuration of metal Cu atoms are analyzed. It is found that the amorphous structures are mainly formed with the three bond-types of 1551,1541 and 1431 in the system; the icosahedral cluster （12 0 12 0） and other basic polyhedra clusters of （12 2 8 2）,（13 1 10 2）,（13 3 8 4）,（14 1 10 3）,（14 2 8 4） and （14 3 6 5） play a critical role in the transition from liquid to glass, the nano-clusters formed in the system are consisted of some basic polyhedra clusters by connecting to each other, and distinguished from those obtained by gaseous deposition and ionic spray. By analyzing pair distribution function g（r） curve, HA bond-types,basic cluster-types and Mean volume per atom ,it is found that the glass transi- tion temperature Tg for liquid metal Cu is about 673K at the cooling rate of 1.0 × 10^14 K/s.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2010年第12期115-120,共6页
Materials Reports
基金
国家自然科学基金资助项目(50571037)
嘉应学院自然科学基金资助项目(08KJ31)
关键词
分子动力学模拟
液态金属Cu
Q-SC多体势
纳米团簇结构
molecular dynamics simulation, liquid metal Cu, Q-SC many-body potential, structure of nanocluster
