Solution of Fick's law with concentration dependent diffusion

Can FEATool be used to solve Fick's diffusion PED using non-linear concentration dependent diffusion?  I have tried a 1D problem using realistic numbers (C0 of 1e20 and D0 of 1e-11) using a flux boundary on the left and get a result, but only after hours of solution time (time dependent, internal solver, 0.2 time step for 1000 total time)
Any comments to help me understand this would be welcome.
Thanks.

Figured it out myself.......learning curve problem.

Hi,

I am trying to solve this problem too. Could you please share your solution.
Thanks.
Mike

Sure.  TKdiff4.fea solves the non linear 1d diff equation with constant surface concentration using internal solvers.  TKdiff4_fenics.fea solves the same one using fenics.  I have a version that calculates a deposition, then a drive redistribution from the dep result, but it is an m file and needs the registered version of FEATool.
Tom

tkdiff4.featkdiff4_fenics.fea