Lacroix B, Godinho V, Fernández A
Instituto de Ciencia de Materiales de Sevilla, CSIC - Universidad de Sevilla, Av. Américo Vespucio 49, 41092, Seville, Spain.
Instituto de Ciencia de Materiales de Sevilla, CSIC - Universidad de Sevilla, Av. Américo Vespucio 49, 41092, Seville, Spain.
Micron. 2018 May;108:49-54. doi: 10.1016/j.micron.2018.02.004. Epub 2018 Feb 15.
In this work, (scanning) transmission electron microscopy has been used to study the nanostructure of porous cobalt coatings obtained by magnetron sputtering using helium as process gas. This nanostructure consists of closed pores of different nanometric size (about 4-20 nm) that are distributed all over a nanocrystalline Co matrix and filled with the deposition gas. Spatially resolved electron energy-loss spectroscopy analysis was applied to measure and map, with high lateral resolution, the relevant physical properties (density, pressure and He-K edge shift) of helium trapped inside these individual nanopores, in order to provide new insights about the growth mechanism involved in such systems. In particular, a coefficient of proportionality, C = 0.039 eV nm, between the blue shift of the He K-edge and the He density has been found. In addition, very high He densities (10-100 at./nm) and pressures in the gigapascal range (0.05-5.0 GPa) have been measured. The linear dependence of these parameters as a function of the inverse radii obeying to the Laplace-Young law for most of the pores suggests that their formation during the coating's growth takes place in regime of elastic deformation of the Co matrix.
在这项工作中，（扫描）透射电子显微镜已被用于研究以氦气作为工艺气体通过磁控溅射获得的多孔钴涂层的纳米结构。这种纳米结构由分布在整个纳米晶钴基体上、尺寸不同（约4 - 20纳米）的封闭孔隙组成，孔隙中充满了沉积气体。应用空间分辨电子能量损失谱分析，以高横向分辨率测量并绘制这些单个纳米孔内捕获的氦气的相关物理性质（密度、压力和氦K边位移），以便为这类系统中涉及的生长机制提供新的见解。特别地，发现了氦K边蓝移与氦密度之间的比例系数C = 0.039 eV·nm。此外，还测量到了非常高的氦密度（10 - 100原子数/纳米）和吉帕斯卡范围内的压力（0.05 - 5.0 GPa）。对于大多数孔隙，这些参数作为半径倒数的函数的线性依赖关系符合拉普拉斯 - 杨定律，这表明它们在涂层生长过程中的形成发生在钴基体的弹性变形状态。
