Pure metals can have ultrafast growth rates from their melts, such as a crystal of pure nickel that grows at a rate reaching 70 m s⁻¹. These extraordinary growth rates suggest that metallic crystals might provide the next generation of phase-change materials. The huge crystal growth rates of metals are the consequence of kinetics without activated control, in sharp contrast to the prediction of the ‘classic’ theory of crystal growth. While the existence of barrierless growth kinetics is now well established in atomic melts, the physical explanation for the absence of an activation barrier to ordering remains unclear. It is something of a paradox that diffusion in the liquid metal is governed by thermal activation while the movement of the same atoms organizing into a crystal is not. Here we use computer simulations of crystallization in pure metals to explicitly resolve the origin of the barrierless growth kinetics.

纯金属可从其熔体中获得超快的生长速率，例如纯镍晶体以70 m s ^-1的速率生长。这些惊人的增长率表明，金属晶体可能会提供下一代相变材料。金属的巨大晶体生长速率是没有激活控制的动力学结果，这与晶体生长“经典”理论的预测形成鲜明对比。尽管现在在原子熔体中已经很好地确定了无障碍生长动力学的存在，但尚不清楚对于有序的活化障碍不存在的物理解释。液态金属中的扩散受热激活支配，而组织成晶体的相同原子的运动则不受支配，这是一个悖论。在这里，我们使用纯金属结晶的计算机模拟来明确解决无障碍生长动力学的起源。