I'm not sure I understand your question, however, I hope this will help you.

https://www.finishing.com/515/96.shtml

Dear Kumaresan Natesan,

Interpretation of EDX with Example is given below :

Weight% = 100 * weight of one component (element) / weight of entire sample.

Atomic% = 100 * number of atoms of one component / total number of all atoms in sample

Atomic weight% is calculated from the Element Weight% by dividing each element weight% by its atomic weight, do this for all elements in the sample which will give a list of Atomic Proportions. Sum of these together to obtain a Total Atomic weight. Then, for each Element in the sample divide its Atomic Proportion by the Total and then multiply it by 100.

EDX of CdS is explained below:

1. Cd: 79.15 wt%

2. S: 20.85 wt%

Divide each by their Atomic weights Cd (112.411) and S (32.065)

1. Cd: 79.15 / 112.411 = 0.704

2. S: 20.85 / 32.065 = 0.650

Sum

1. Cd: 0.704

2. S: + 0.650

1.354

Divide each by the Sum (1.354) and turn into Atomic%

1. Cd: 0.704 / 1.354 * 100 = 51.99 at.%

2. S: 0.650 / 1.354 * 100 = 48.01 at.%

The Average Atomic% of Cd:S was found to be almost stoichiometric in nature with the Cd% of 52 and S% of 48.

You can also see my answer to the question about "Can any one help how to interprite edx data?" in a previous thread, in the link below.

https://www.researchgate.net/post/Can_any_one_help_how_to_interprite_edx_data#view=5b65d5f0c7d8abc5c3093440

I hope I have answered your question.

With Best Wishes,

Samir G. Pandya

At% means the fraction of number of atoms - in ZnO this should be close to 50:50.

Wt% means the fraction of weight per element. As Zn is much heavier (65.4u) than O (16.0u) you would get about 80:20 for the weight fractions.

Chemists typically use at% in line with their chemical formulas, metallurgists prefer wt% so they can use weight scales to mix alloys.

Are the numbers of a EDS spectra characterization reliable?