Picosecond time‐resolved measurements of crystallization in noble metals
Picosecond time‐resolved measurements of crystallization in noble metals
复制标题
贵金属结晶的皮秒时间分辨测量
DOI：
10.1063/1.342586
复制
发表时间：
1989
影响因子：
3.2
通讯作者：
F. Spaepen
中科院分区：
文献类型：
--
作者：
C. MacDonald;A. M. Malvezzi;F. Spaepen
通过监测脉冲激光淬火过程中皮秒时间尺度上反射率的变化，测量了纯金属的结晶速率。多层膜被用来建立反射率的瞬时下降对应于熔化。在激光照射区域上使用俄歇电子能谱进行的深度分析显示了层的完全混合，这只能通过熔化发生。测得结晶速度高达100 m/s。这些生长速度太大，不可能是由液态扩散控制的结晶过程的结果。基于碰撞限制结晶生长模型的计算机模拟结果与测量结果一致。
Crystallization rates in pure metals have been measured by monitoring changes in reflectivity on a picosecond time scale during pulsed laser quenching. Multilayered films were used to establish that the transient decreases in reflectivity correspond to melting. Depth profiling with Auger electron spectroscopy on laser‐irradiated areas showed complete mixing of the layers, which could only have occurred by melting. Crystallization velocities as high as 100 m/s were measured. These growth speeds are too large to be the result of a crystallization process governed by liquid state diffusion. The results of computer simulations based on a collision‐limited growth model for crystallization were consistent with the measurements.