COMSOL for thin film heterostructures

[momar]

I am trying to model intrinsic stress of some thin film heterostructures. As I am not a modeler but an experimentalist/processor by trade, I would prefer to minimize the amount of time I spend banging my head against the wall trying to find out if this software is appropriate. So, my question is whether COMSOL is appropriate for this. I note that they include thermal expansion coefficient in the materials database, but I did not see lattice parameters/crystal structures etc. If so, I also need to know if it is possible to include model amorphous materials? I suppose if not I can manually alter some of the parameters slightly to force the model to agree with the raman stress measurements.

Thanks.

 

[PerennialII]

Comsol is essentially a continuum mechanics based FE software package, and limitations of what you can do by modeling a material as a continuum apply. So stresses arising from temperature changes (even in a complex heterogeneous microstructure) as long as modeled as a continuum are fairly easy to extract, but the intrinsic part is more difficult. I suppose if you can "squeeze" your mechanisms responsible for the intrinsic part to a continuum modeling envelope it'll work great, but there are no means to directly model lattices or microstructures (naturally can create complex geometric structures and place anisotropic properties on them, if this suffices)[or model the underlying mechanisms in a "coupled multiphysics framework" which give rise to intrinsic residual stresses]. With respect to FE based means Comsol is in my mind one of the better tools for this since it has very few limitations (as long as stay within FEM & continuum of sorts) and can be easily extended. The amorphous point follows the same limitations, if your material can be said to obey a continuum law of some sort it'll work.

 

[remir]

hi

i'am start using consol to modeling heterostructures thin films (BST deposited ba sol-gel method). i have problem with modeling structures in 3d. do you have samthing pdf with examples or tutorials. pleas contact with me.

 

[PerennialII]

Do you have access to the official documentation? The "Model Library" docs are a big help in getting started. The official website contains a model library as well.

 

[remir]

Unfortunately I don't have access to the official documentation yet

 

[PerennialII]

...you could perhaps inquire about the tutorials & models that are presented at the official site, select one which would "match" your problem to get you going. Or then use the model library that comes with the installation, those are a big help in trying to understand Comsol.