There is no need to define elasticity matrix, if you are using built-in materials in Comsol. But you should enter the value of relative permittivity even for most built-in materials. Please bear in mind that this value for most of metal is equal to 1. So it is only required that you enter for permittiviy in chosen material. Good luck!

There is no need to define elasticity matrix, if you are using built-in materials in Comsol. But you should enter the value of relative permittivity even for most built-in materials. Please bear in mind that this value for most of metal is equal to 1. So it is only required that you enter for permittiviy in chosen material. Good luck!

hello mehdi you don't know how to define the coupling matrix of ferroelectric. if you have any  paper speaking about ?

Dear Rajagopalan, I had myself this problem when trying to simulate with COMSOL some electromagnetism problems involving iron-oxide magnetic nanoparticles on an aluminum alloy 2024 substrate.

I can provide you with the values of relative permittivity that I used for the Al alloy 2024 substrate (the values for other alloys or pure Al should not be far from these):  

a) 1.44 from this reference (N. M. Ibrahim and I. H. a. Fattah, “Narrow-beam aluminum-mirrored fiber optical-taps with controllable tapped power,” IEEE J. Sel. Top. Quantum Electron., vol. 2, no. 2, pp. 221–225, Jun. 1996. DOI: 10.1109/2944.577366); and

b) 8.00 from this reference (H. Kanayama, D. Tagami, K. Imoto, and S. Sugimoto, “Finite element computation of magnetic field problems with the displacement current,” J. Comput. Appl. Math., vol. 159, no. 1, pp. 77–84, Oct. 2003. DOI: 10.1016/S0377-0427(03)00560-0)

hii Jose Ignacio Rojas Gregorio 

can u please give some knowledge about coupling matrix if u know or any reference of papers. I m having same problem regarding the PZD silicon nitride Si3N4.

Thanks.