摘要
采用磁控溅射技术制备了调制波长从18-108 nm的Al/Ta金属多层膜,并研究多层膜沉积过程中的截面结构形貌演化,实验表明,薄膜结构形貌演化分为四个阶段：孕育,萌生,发展和湮灭,可能是因为弹性失配引起的,并且随调制波长的增加呈现逐渐减弱的趋势。单向拉伸实验表明,这些结构形貌的非稳定区域严重影响力学行为,非稳区域往往是潜在的裂纹萌生区域。
Al/Ta multilayers with bilayer thickness ranging from 18 to 108 nm were fabricated by dc magnetron sputtering technique. By evaluating the cross -sectional transmission electron microscopy images of the nanoscale multilayers, the stabilization of the deposited microstructure morphology were investigated. For the first time, a unique evolution process of the structure instabilities in metal multilayers was observed and evaluated, in which four stages were identified. Farther analysis of the four sages found that microstructure morphological instabilities were dominated by elastic misfit. The formation of microstructure morphological instabilities was deducted to find the characterization factors in Al/Ta multilayers with various bilayer thicknesses. The Al/Ta multilayers deformed in uniaxial tension test show that microstructure morphological instabilities strongly influence the mechanical property. The zones of instabilities break down the continuum of films and are key points of formation of cracks.
基金
Acknowledgement The present work was s upported by the National Basic Research Program of China （2010CB631002） , the National Natural Science Foundation of China （50501019,50701034） , Program for New Century Excellent Talents in University （NCET-07-0665） and the Fundamental Research Funds for the Central Universities.
