publications by Stefano Curtarolo.

Papers Published

1. Kolmogorov, A.N. and Curtarolo, S., Theoretical study of metal borides stability, Phys. Rev., B, Condens, Matter Mater. Phys. (USA), vol. 74 no. 22 (2006), pp. 224507 - 1 [PhysRevB.74.224507] .
   (last updated on 2007/04/06)

   Abstract:
   We have recently identified metal-sandwich (MS) crystal structures and shown with ab initio calculations that the MS lithium monoboride phases are favored over the known stoichiometric ones under hydrostatic pressure [Phys. Rev. B 73, 180501(R) (2006)]. According to previous studies synthesized lithium monoboride (LiB_y) tends to be boron deficient (y=0.8-1.0), however, the mechanism leading to this phenomenon is not fully understood. We use a simple model to simulate this compound with ab initio methods and discover that the boron-deficient lithium monoboride is a remarkable adaptive binary alloy: it has virtually no energy barriers to change its composition post synthesis within a small but finite range of y at zero temperature. Having demonstrated that the model well explains the experimentally observed off-stoichiometry, we next compare the LiB_y and MS-LiB phases and find that the latter have lower formation enthalpy under high pressures. We also systematically investigate the stability of MS phases for a large class of metal borides. Our results suggest that MS noble-metal borides are less unstable than the corresponding AlB₂-type phases but not stable enough to form under equilibrium conditions

   Keywords:
   ab initio calculations;crystal structure;enthalpy;lithium compounds;stoichiometry;