Grain boundary grooving in thin films revisited: The role of interface diffusion
Grain boundary grooving in thin films revisited: The role of interface diffusion
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DOI：
10.1016/j.actamat.2014.02.008
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发表时间：
2014-05
期刊：
影响因子：
9.4
通讯作者：
D. Amram;L. Klinger;Nimrod Gazit;H. Gluska;E. Rabkin
中科院分区：
文献类型：
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作者：
D. Amram;L. Klinger;Nimrod Gazit;H. Gluska;E. Rabkin
采用电子束沉积法在蓝宝石衬底上共面取向生长镍薄膜。所沉积的薄膜表现出一个迷宫状的双晶显微结构，由两个孪晶取向的交织晶粒。样品在700 °C退火导致Ni膜增厚。同时，在晶界热槽附近的表面区域的质量赤字进行了观察。观察到的凹槽的形状是非常不同的，从经典的Mullins模型预测。我们建立了一个热刻槽的模型，同时膜增厚由于镍扩散沿着镍-蓝宝石界面，这符合实验结果。这些结果表明，自扩散的金属原子沿着金属陶瓷界面起着重要的作用，在薄膜中的质量传输。讨论了快速界面扩散对薄膜热稳定性的影响。
Thin nickel (Ni) films were grown onc-plane-oriented sapphire substrates by electron-beam deposition. The as-deposited films exhibited a mazed bicrystal microstructure consisting of interwoven grains of two twinned orientations. Annealing of the specimens at 700 °C resulted in the thickening of the Ni film. At the same time a mass deficit in the surface regions near grain boundary thermal grooves was observed. The shape of the observed grooves was very different from that predicted by the classical Mullins model. We developed a model of thermal grooving with simultaneous film thickening due to Ni diffusion along the Ni–sapphire interphase boundary, which agreed well with the experimental results. These findings demonstrate that self-diffusion of metal atoms along the metal–ceramic interface plays an important role in mass transport in thin films. Some implications of fast interphase boundary diffusion for the thermal stability of thin films are discussed.