Trice Justin, Favazza Christopher, Thomas Dennis, Garcia Hernando, Kalyanaraman Ramki, Sureshkumar Radhakrishna
Department of Physics, Washington University, St. Louis, Missouri 63130, USA.
Phys Rev Lett. 2008 Jul 4;101(1):017802. doi: 10.1103/PhysRevLett.101.017802. Epub 2008 Jul 2.
When an ultrathin metal film of thickness h (<20 nm) is melted by a nanosecond pulsed laser, the film temperature is a nonmonotonic function of h and achieves its maximum at a certain thickness h*. This is a consequence of the h and time dependence of energy absorption and heat flow. Linear stability analysis and nonlinear dynamical simulations that incorporate such intrinsic interfacial thermal gradients predict a characteristic pattern length scale Lambda that decreases for h>h*, in contrast to the classical spinodal dewetting behavior where Lambda increases monotonically as h2. These predictions agree well with experimental observations for Co and Fe films on SiO2.
当厚度h（<20纳米）的超薄金属薄膜被纳秒脉冲激光熔化时，薄膜温度是h的非单调函数，并在某一特定厚度h处达到最大值。这是能量吸收和热流对h和时间依赖性的结果。纳入这种固有界面热梯度的线性稳定性分析和非线性动力学模拟预测了一个特征图案长度尺度Λ，对于h>h，Λ会减小，这与经典的旋节线失稳行为相反，在经典行为中Λ随h²单调增加。这些预测与SiO₂上Co和Fe薄膜的实验观察结果吻合良好。
