2PPRIME - Institut Pprime (Institut PPRIME : Recherche et Ingénierie en Matériaux, Mécanique et Energétique
SP2MI Téléport 2
Boulevard Pierre et Marie Curie
BP 30179
86962 FUTUROSCOPE CEDEX - France)
Université de Poitiers : UPR3346 (15, rue de l'Hôtel Dieu - 86034 Poitiers Cedex - France)
Abstract : Atomistic calculations of the ½〈1 1 0〉 screw dislocation core structure in MgO have been carried out showing the influence of high pressure (up to 100 GPa) on the core spreading. Calculations rely on a periodic arrangement of dislocation quadrupoles. Comparison between first principles and pairwise potential simulations show a remarkable agreement. Our results confirm that the dislocation core evolves from a spreading in {1 1 0} (at low pressure) to a narrower configuration spread in {1 0 0} as pressure increases. The periodic dipole method enables us also to record the pressure induced core energy variations.