question about NDSolve for Diffusion equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg102823] question about NDSolve for Diffusion equation*From*: Nam Viet Nguyen <teivn109 at yahoo.com>*Date*: Fri, 28 Aug 2009 00:46:17 -0400 (EDT)

Hello, I am trying to use the NDSolve of Mathematica to solve the diffusion equation which has diffusivity dependence to concentration. My work is dealing with phosphorous diffusion into silicon. The equation is d''C/dt^2 = d( C^2 *dC/dx)/dx where C= C(x,t). In my problem, the initial conditions should be : C(x,0)=0, C(0,0) = 0, C(0,t) = Cs if t > 0. If I used the NDSolve, there is a error message, the Initial conditions are not consistent. I dont known how to go further as I have checked again and again the initial conditions are fine. Your helps anf advice are gratefully acknowledged, Nam Nguyen. Stuttgart, Germany

**Follow-Ups**:**Re: question about NDSolve for Diffusion equation***From:*"Ingolf Dahl" <ingolf.dahl@telia.com>