Dear,

You can get access to the atom's number by using RBS analysis. The main information given by this technique are the percentage of each element and also the number of atoms per area unit. So if you know the thinkness of your films, you will be able to calculate easily the atom's density.

I hope this answer is useful for you. Best regards

Dear Abdellatif Bachar

Thank you for your reply, what about the type of these atoms (Cu atoms or S atoms) in the plane, how can I know them? You mean "the percentage of each element " is the type of these atoms?

The answer can be found from crystal structure analysis. First, find the bulk structure of your material. Second, using either pencil and paper or a crystal structure program, draw a unit cell of that structure. The manual method is a good exercise problem for a first year grad course in materials science. Third, extend that crystal structure at least four unit cells in the three Cartesian directions. Finally, to get the (008) plane, follow the rules of Miller index notations to make the cut through your extended lattice structure. This is a good advanced exercise problem for a first year grad course in materials science.

The exercise is tedious and requires care. The skill you gain to do the analysis properly and the insights the exercise provides you to crystallography make the effort worth while.

Dear Prof. Jeffrey J Weimer

Thank you very much for your excellent explanation.

Best regards

Fayroz