Dear Dr. Tahere Golizadeh,

if you are interested in the chemical composition of the extreme surface layer (2-5 microns) of your sample, so that you can also know the oxidation state of the elements and be able to identify the individual chemical compounds using a non-destructive measure, I suggest you the X-Ray Photolelectron Spectrometry technique (XPS) also hnown as Electron Spectroscopy for Chemical Analysis (ESCA). Depending on your reserch and the instrument model, you may have the limit of the sample size.

You can find more info at the folllowing web sites:

- https://www.phi.com/surface-analysis-techniques/xps-esca.html

- https://xpssimplified.com/whatisxps.php

Best regards, Pierluigi Traverso.

Hi Tahere Golizadeh

I agree with Pierluigi Traverso , also you can perform a SEM/EDS characterization to obtain the elemental composition and mapping of the distribution of each element in your coating.

Regards!

EDS is a semi-quantitative technique, it doesn't give the exact composition of the thin layer, I suggest you use X-ray fluorescence spectrometry which is, in my opinion, more precise.

Bests!

Laser diffraction and X-ray fluorescence spectrometry are best method to determine thin layer composition

Hi!

There is no absolute method for exactly determining the composition before deposition. But you can just estimate it by the following.

For example you are planning to deposit a Cu & Ni alloy, along with some additives.

a) prepare your electrolyte with all your salts except for the nickel source and do a potentiodynamic study. Say, at 1 V you are getting 1 ampere current.

b) now prepare your electrolyte with all your salts except for the copper source and do a potentiodynamic study. Say at 1 V you are getting 2 ampere current.

c) Now if you are planning to deposit a copper nickel alloy at 1 V, your composition of Cu: Ni must be in the ratios of current i.e. 1:2. so 33% copper and 66% Nickel.

Side Note 1) In case you are planning to deposit any of the Fe, Co, Ni then you cannot estimate the concentrations in the above manner because of the well know anomalous behavior which is shown by them.

Side Note 2) Again keep in mind that both Cu and Ni are bivalent. So you if plan to deposit a monovalent and a trivalent ion, or a bivalent and a trivalent etc. etc., factor-in their valency before you can come to conclusion. For example, you pass 3 amps of current for Cr3+ and 3 amps for silver Ag1+ then you will get 3 times more mass of silver than chromium. I hope you get the situation!

Again like I said, there is no absolute method for determining this compositions beforehand but this method will give some room for you to breathe as you can have a quick start rather then being completely in the dark.