  Temperature changes during the growth of lamellar polymer crystals give rise
to steps on the surface of the crystals. It has recently been suggested that
these steps could provide important insights into the mechanism of polymer
crystallization. In particular, a characterization of the profiles of these
steps might reveal the fixed-point attractor that underlies a recently proposed
crystallization mechanism. Here we examine this hypothesis by performing
simulations of such temperature jumps using the Sadler-Gilmer model. We find
that for this model the step profiles do reveal the fixed-point attractor.
However, for temperature decreases they also reflect the rounding of the
crystal edge that occurs in this model and for temperature increases they also
reflect the fluctuations in the thickness present in the crystal. We discuss
the implications of these results for the interpretation of experimental step
profiles.
