Pressure effects on icosahedral short range order in undercooled copper

There is not a wide consensus on the role played by the icosahedral short range order on the stability of undercooled simple metals. The scenario is even less clear for undercooled metals under external pressure. Classical molecular dynamics simulations are performed to explain experimental results recently obtained on liquid and undercooled liquid copper under pressure. The atomic configurations are characterized by a common neighbor analysis to reveal the icosahedral short range order and its relation with external pressure. External pressure increases the probability to find atomic bonds with icosahedral symmetry both in the liquid and in the undercooled copper. (C) 2009 Elsevier Masson SAS. All rights reserved.