Bulk diffusion of metal particles on ceramic substrates
Bulk diffusion of metal particles on ceramic substrates
复制标题
金属颗粒在陶瓷基板上的体扩散
作者：
P. L. Gal;B. Smith;G. Owen
沉积在陶瓷表面的金属颗粒或薄膜的动力学行为在多相催化、陶瓷金属钎焊和微电子技术中具有重要意义。例如，现有的关于金属颗粒烧结或分散的理解往往是基于静态的、室温的非原位研究，这些研究只考虑了金属1-3的表面铺展。在这里，我们从原位电子显微镜中提供了金属颗粒在陶瓷衬底主体中扩散的证据。我们研究了在不同氧化还原气氛(氢气、氧气和一氧化碳)中无定形氧化铝表面小铜粒的动力学。在氧气中，颗粒首先扩散通过基材，形状变化不大，但随后颗粒横向扩散(通过表面或亚表面扩散)，形成较低表面能的构型。我们认为，这些扩散过程在涉及类似材料组合的电子应用中可能是重要的。
THE dynamical behaviour of metal particles or films deposited on ceramic surfaces is of great importance in heterogeneous catalysis, metal brazing of ceramics and microelectronics. The existing understanding of, for example, metal particle sintering or dispersion has tended to be based on static, room-temperature ex situ studies, which have considered only surface spreading of the metal1–3. Here we present evidence from in situ electron microscopy for the diffusion of metal particles through the bulk of a ceramic substrate. We have studied the dynamics of small copper particles on the surface of amorphous alumina in various oxidizing and reducing atmospheres (hydrogen, oxygen and carbon monoxide). Under oxygen, particles first diffuse through the substrate with little change in shape, but at later times particles spread laterally (by surface or sub-surface diffusion) to a configuration of lower surface energy. We suggest that these diffusion processes may be important in electronics applications, which involve similar combinations of materials.