Summary
• Glicksman et al. observe a 10% - 15% discrepancy in the Ivantsov relation for SCN
over the range 0.5 K < DT
< 1.0 K
• Horvay-Cahn exact 2-fold solution gives an amplitude-dependent correction to the
Ivantsov relation
• An approximate 4-fold solution can be obtained to second order in
e, with S = S(0) + e2 S(2)/2 + ...
• LaCombe et al. measure a shape factor e » -0.008 for P »
0.004
• Using e
= 0.008 gives S/S(0) - 1 =
0.09
• Assuming the dendrite tip is similar to the [001] portion of the anisotropic
equilibrium shape gives e
= - 0.011 ± 0.003