Third Order Elastic Constants and Debye Temperature of MgB2 Under Different Pressure: First-Principles Methods

摘要

The second-order elastic constants (SOECs) and third-order elastic constants (TOECs) of superconducting MgB2 are investigated by first principles methods combined with homogeneous deformation theory. The Anderson-Gruneisen parameter is obtained from the SOECs and TOECs. The obtained value is 2.13, that is in consistent with the experimental result. The effective elastic constants and Debye temperature are also predicted from SOECs and TOECs, which increase with the increasing of pressure.