In this study we have incorporated two time scales into the phase field
crystal model of a binary alloy to explore different solute trapping properties
as a function of crystal-melt interface velocity. With only diffusive dynamics,
we demonstrate that the segregation coefficient, K as a function of velocity
for a binary alloy is consistent with the model of Kaplan and Aziz where K
approaches unity in the limit of infinite velocity. However, with the
introduction of wave like dynamics in both the density and concentration
fields, the trapping follows the kinetics proposed by S. Sobolev[Phys. Rev. A.
199:383386, 1995.], where complete trapping occurs at a finite velocity.