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Anisotropic electrical conductivity

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Hello,

I hope my question is quite simple for skilled people in Comsol.
I would like to perform modeling of a stack of conductive thin film. Thickness of the films are in the range of 100 nm, while the length of the system is about 1 m. Therefore, in order to avoid having a distorted mesh, I'd rather multiply the thickness of the film by a given z factor, and multiply the conductivity in that direction by the same factor... but not in the other direction.
Is there an easy way to define an anisotropic electrical conductivity?
Best regards
Fabien

4 Replies Last Post 08.06.2012, 00:56 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 07.06.2012, 02:08 GMT-4
Hi

first I would advise you to use a more recent version, then yes COSMOL allows for full tensor development of all related parameters, by default its in "isotropic" mode, check the node pull down menus

stacked thin film of nanometers on 1m long objct will be a challenge because of the dimansional ratio, and this for any FEM programme (limitations of the binary representation of number values) you should consider if there is not ways to use the thin film boundary conditions as probably you have no significant effects transverse to the thickness, or to use a coupled model 2D local in the film thickness and project that onto a 3D model

--
Good luck
Ivar
Hi first I would advise you to use a more recent version, then yes COSMOL allows for full tensor development of all related parameters, by default its in "isotropic" mode, check the node pull down menus stacked thin film of nanometers on 1m long objct will be a challenge because of the dimansional ratio, and this for any FEM programme (limitations of the binary representation of number values) you should consider if there is not ways to use the thin film boundary conditions as probably you have no significant effects transverse to the thickness, or to use a coupled model 2D local in the film thickness and project that onto a 3D model -- Good luck Ivar

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Posted: 1 decade ago 07.06.2012, 11:41 GMT-4
Thank you for your reply.
I'll try to figure out with my company whether I can access a more recent version.
If so, how do I do to implement a tensor for the electrical conductivity :
[x 0 0] [0 y 0] [0 0 z] in the "electrical conductivity" value of the material?
Best regards
Fabien
Thank you for your reply. I'll try to figure out with my company whether I can access a more recent version. If so, how do I do to implement a tensor for the electrical conductivity : [x 0 0] [0 y 0] [0 0 z] in the "electrical conductivity" value of the material? Best regards Fabien

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 08.06.2012, 00:56 GMT-4
Hi

either you define it in the materials (check the material DB there should be some examples therein) or you define it in the main EC physics Electric conductivity User defined Anisotropic or whatever is relevant. You can also define a user coordinate system, it does not need to be the cartesian global x,y,z orientation

--
Good luck
Ivar
Hi either you define it in the materials (check the material DB there should be some examples therein) or you define it in the main EC physics Electric conductivity User defined Anisotropic or whatever is relevant. You can also define a user coordinate system, it does not need to be the cartesian global x,y,z orientation -- Good luck Ivar

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 08.06.2012, 00:56 GMT-4
Hi

either you define it in the materials (check the material DB there should be some examples therein) or you define it in the main EC physics Electric conductivity User defined Anisotropic or whatever is relevant. You can also define a user coordinate system, it does not need to be the cartesian global x,y,z orientation

This is so in my 45.2a I'm not sure everything was implemented in the early 4.0

--
Good luck
Ivar
Hi either you define it in the materials (check the material DB there should be some examples therein) or you define it in the main EC physics Electric conductivity User defined Anisotropic or whatever is relevant. You can also define a user coordinate system, it does not need to be the cartesian global x,y,z orientation This is so in my 45.2a I'm not sure everything was implemented in the early 4.0 -- Good luck Ivar

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