High-pressure phase transitions and equations of state in NiSi. III. A new high-pressure phase of NiSi

Wood, I.G.; Ahmed, J.; Dobson, D.P.; Vočadlo, L.

doi:10.1107/S0021889812047085

Figure 5
Enthalpy (here equal to Gibbs free energy) of NiSi phases from athermal VASP simulations as a function of pressure, relative to that of the CsCl structure. The enthalpy curves shown are identical to those given in Fig. 3 of Vocadlo et al. (2012

), with the curve for the new Pmmn phase added (thick dot-dashed line; shown in red in the electronic version of the journal). With increasing pressure the sequence of stable phases of NiSi is now MnP structured [rightwards arrow]

Pmmn phase [rightwards arrow]

CsCl structured, with transition pressures of 21 and 264 GPa, respectively. Note, however, that the free-energy difference between many of the structures is only

5-25 meV atom^-1.