Initial dynamics of a solid–liquid interface within a thermal gradient

In directional solidification experiments an alloy is placed in the thermal gradient assembly and kept stationary to achieve a steady-state thermal profile. During this time an interface motion occurs that is experimentally characterized and shown to generate a solute boundary layer at the interface whose thickness depends on the time the sample is kept stationary before the external velocity is imposed. This boundary layer must be included in the theoretical description of the initial transient during a planar front growth.