Hello,
I am working on laser ablation of silicon and I use “fix-TTM” command to transfer heat from electrons to lattice. In the LAMMPS TTM command, the source energy is replaced by the friction coefficient due to electronic stopping. In order to start simulation at the initial stage, I have to give a certain electron (Te) and lattice(Ta) temperature to my system. I am wondering how can I obtain the temperatures of electrons and lattice as a function of heat source for the initialization. Your advise would be highly appreciated.
Regards,
Leyla
Finding the right parameters, boundary conditions, and initial conditions is indeed a challenging aspect of using fix TTM. I’d recommend revisiting the TTM+MD literature for ideas.
The lattice temperature is given by the temperature/velocity of the atoms, which you’ll need to set. You’ll also need to set an initial condition for your electron temperature. You’ll have to estimate how much energy is deposited into your system prior to the start of your simulation and distribute that energy between the electronic and atomic subsystems in terms of initial temperatures.
Paul
Dear Paul,
Thanks, my question is for a certain amount of energy (i.e. 0.3/cm2), what would be the temperature of electrons.
Regards,
Leyla
We typically leave this kind of exercise up to individual LAMMPS users. Stuff like figuring out what force field parameters to use and how to set initial and boundary conditions can be difficult to figure out for new LAMMPS users, but we see that as the job of the LAMMPS user rather than the job of the code developers.
Paul