金属纳米颗粒在Lu_2O_3薄膜中的应变场分析

Strain Distribution of Metal Nanoparticles Embedded in Lu_2O_3 Film

利用有限元分析法对镶嵌在Lu2O3薄膜中的Au、Cu、Pt、Co金属纳米颗粒的应变场分布进行分析.分析表明:金属纳米颗粒在生长过程中受Lu2O3薄膜的压缩应力作用,从而在纳米颗粒内部和表面产生相应应变,应变分布与金属纳米颗粒的杨氏模量和泊松比有关.杨氏模量大的金属纳米颗粒表面应变和内部应变差异较大;而杨氏模量小的金属纳米颗粒内外应变差相对较小.随着金属纳米颗粒在基体材料内部不断生长,其受到的偏应变也逐渐增大.金属纳米颗粒生长过程中的这种偏应变的存在和变化将极大地影响其内部晶格结构和表面形貌,进而影响金属纳米颗粒的性能.

The strain distributions of Au, Cu, Pt and Co nanoparticles embedded in Lu2O3 matrix were investigated by the finite-element calculations. The simulation results indicated that all of metal nanoparticles incure compressive stress by the Lu2O3 matrix, which thus result in the corresponding strain in the center and at the surface of nanoparticles. The strain distributions are closely related to the Young＇s modulus and poisson＇s ratio of metal nanoparticles and matrix. For the metal nanoparticle with bigger Youngrs modulus, the difference between the strain in the center and that at the surface of the nanoparticles is largerer. While, for the metal nanoparticle with smaller Younffs modulus, the difference between the strainat the surface and that in the center of the nanoparticles is smaller. Meanwhile, with the growth of metal nanoparticles, the deviator strain also increase. This net deviatoric strain distribution may also have a significant influence on the morphology and microstructure of metalnanoparticles, and thus the physical properties of metal nanoparticles.