摘要
针对纳米量级薄膜比热容测定的困难,根据实验值建立了SiO2(100)薄膜物理模型.选取可靠的势能函数描述了分子间的相互作用,采用分子动力学模拟了它的比热容变化规律,在100～600K下给出了厚度在1～5nm的薄膜比热容对温度和厚度的依赖关系.计算结果表明,SiO2薄膜在300K下比热容明显低于相同条件下常规体材料的比热容,且随薄膜厚度的增加而增大;随温度升高,比热容变大,这同体材料是一致的.模拟结果揭示了SiO2薄膜比热容的微尺度效应,与理论分析基本吻合,可为半导体微器件的设计提供资料.
Due to the difficulties of measurement for the specific heat capacities of nano-films, a model of SiO2(100) thin solid films is constructed based on experimental values and a reliable potential function to present the interaction of atoms is chosen. Specific heat capacity is simulated using molecular dynamics. Size and temperature dependent effects of the films with l-5 nm at 100-600 K are described. The specific heat capacities of SiO2 thin films are evidently smaller than those of bulk materials in the same condition and decrease with the reduction of thickness at 300 K. Meanwhile they increase as temperature becomes higher, which is the case with bulk materials. The microscale effect is revealed and the results are in agreement with some theoretical analysis proposed in others' literatures, which offer a reference for the design of micro-devices.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2005年第3期313-315,共3页
Journal of Dalian University of Technology
基金
国家自然科学基金资助项目(59995550-5
50135040).
