Orientation Dependence of Shock Structure with Melting in L-J Crystal from Molecular Dynamics
Abstract
We use molecular dynamics to study the structure of steady shock waves with melting transition traveling along the < 100 >, < 110 >, and < 111 > directions in the Lennard-Jones (L-J) perfect fcc crystal. Unlike shock waves in gases and fluids, solid shocks exhibit oscillatory behaviour of profiles within the front that persists even in the strong shocks with melting. Surprisingly, shock wave along the < 100 > direction compresses the L-J crystal to the final overheated solid state in contrast to < 110 > and < 111 > cases wherein the crystal melted at the same shock velocity us = 4.39 km/s. Moreover, the < 110 > and < 111 > melting shock waves differ widely in the front structure: the < 111 > profile without oscillations is closely similar to that of the fluid shocks, whereas the < 110 > shock exhibits a steady precursor of solitary wave train. The evolution of velocity and pair distribution functions across the shock layer are explored to study the shock-induced structure transformations and melting transition occuring within the region of length roughly (10div 30)σ, σ = 3.405.{A}.
- Publication:
-
Progress of Theoretical Physics Supplement
- Pub Date:
- 2000
- DOI:
- 10.1143/PTPS.138.223
- Bibcode:
- 2000PThPS.138..223Z