How can I convert %atomic F to %oxides from EDS analysis?

Joaquín Cafieri To convert the percentage of atoms (atomic %) to the percentage of oxides from an Energy Dispersive X-ray Spectroscopy (EDS) analysis, you need to follow a systematic approach based on stoichiometry and the chemical composition of the oxides. Here is a step-by-step outline for this conversion:

Steps to Convert Atomic % to Oxide % from EDS:

Obtain Atomic Percentages from EDS:The EDS spectrum provides the atomic percentages (% atomic) for each element present in the sample.

Identify the Oxide Form of Each Element: For each element (such as Si, Al, Fe, etc.), you need to know its typical oxide form. For example:Si → SiO₂ Fe → Fe₂O₃ or Fe₃O₄ (depending on the oxidation state) Mg → MgO Al → Al₂O₃ The goal is to express each element in terms of its oxide, which requires knowledge of its stoichiometry in the oxide.

Convert Atomic % to Oxide Formula Weight: For each element, calculate the molecular weight of the oxide based on its atomic weight and the stoichiometric formula. For example:SiO₂: Si = 28.085 g/mol, O = 16.00 g/mol. Molecular weight of SiO₂ = 28.085 + 2 × 16.00 = 60.085 g/mol. Fe₂O₃: Fe = 55.845 g/mol, O = 16.00 g/mol. Molecular weight of Fe₂O₃ = 2 × 55.845 + 3 × 16.00 = 159.685 g/mol.

Calculate the Weight Fraction of Each Element in the Oxide: For each element, calculate its weight fraction in the oxide. For example, for SiO₂:Fraction of Si in SiO₂ = 28.085 / 60.085 ≈ 0.467 (46.7% by weight) Fraction of O in SiO₂ = 2 × 16.00 / 60.085 ≈ 0.533 (53.3% by weight) Repeat for each element and its corresponding oxide.

Multiply the Atomic % by the Weight Fraction: For each element, multiply its atomic percentage (from the EDS analysis) by the weight fraction of that element in the oxide. For example, if the atomic % of Si from EDS is 30%, the weight contribution of Si in SiO₂ is:\text{Oxide % of Si} = 30\% \times 46.7\% = 14.01\%

Sum the Contributions of All Elements:After performing this calculation for all the elements in the sample, sum up the contributions to get the total oxide content for each oxide type.

Convert to Total % Oxides:Finally, the total percentages of all the oxides in your sample will give you the oxide composition by weight.

Example:

Let’s say you have an EDS spectrum with the following atomic percentages for a sample:

Si: 40%
Fe: 25%
Mg: 35%

Now, you would convert these to oxides:

Si: Convert to SiO₂Atomic % of Si = 40% Fraction of Si in SiO₂ = 0.467 Oxide % of Si in SiO₂ = 40%×46.7%=18.68%40\% \times 46.7\% = 18.68\%40%×46.7%=18.68%

Fe: Convert to Fe₂O₃Atomic % of Fe = 25% Fraction of Fe in Fe₂O₃ = 2×55.845/159.685≈0.6982 \times 55.845 / 159.685 \approx 0.6982×55.845/159.685≈0.698 Oxide % of Fe in Fe₂O₃ = 25%×69.8%=17.45%25\% \times 69.8\% = 17.45\%25%×69.8%=17.45%

Mg: Convert to MgOAtomic % of Mg = 35% Fraction of Mg in MgO = 24.305/40.304≈0.60324.305 / 40.304 \approx 0.60324.305/40.304≈0.603 Oxide % of Mg in MgO = 35%×60.3%=21.11%35\% \times 60.3\% = 21.11\%35%×60.3%=21.11%

Result:

Oxide % SiO₂ ≈ 18.68%
Oxide % Fe₂O₃ ≈ 17.45%
Oxide % MgO ≈ 21.11%

Total oxide composition would be the sum of these values for a complete conversion.

Important Notes:

Accuracy: The accuracy of the conversion depends on the precision of your atomic percentage data and the correct stoichiometric relationships for each oxide.
Complexity of Oxides: Some elements may form complex oxides with varying stoichiometries (e.g., mixed metal oxides or spinels), which would require more detailed analysis.
EDS Calibration: Ensure that the EDS system is properly calibrated for accurate atomic percentage readings.

This process allows you to convert atomic percentages to oxide percentages, which is useful for characterizing the material composition, especially when dealing with oxidized or ceramic materials.

Does anyone have a photo of the eggs of Harpagifer bispinis?

What can be the impact of the periodic publication of antimicrobial susceptibility patterns in analyzing the results of the samples?

Adding a spotlight ends by deleting my article?

Should be "pay-to-publish" journals removed from WoS and Scopus?

Connect CX-Programmer with Factory I/O?

Tensile behaviour of UHPFRC, HPFRCC, SHCC for training neural networks?

How to compare two related proprotions (pretest-posttest) with different size population?

What is the recommended maximum number of sessions at tDCS?

How do I process the otucomes of likert scale of two independent groups (experimental and control) both with pretest and posttest?

Is there research on social networks with social capital measured with the position generator by Lin & Dumin (1986) using social network software ?

Why results of ROS flurescence are negative as there was no bacteria within?

Why aren't most metal oxides insoluble in water?

Why chloride turns into chlorine gas in a Downs cell?

How to calculate the molar proportions of the oxides from the XRF analyses?

What is the solubility of Iron (+3) in Bismuth Oxide?

Addition of EDTA during the synthesis of copper nanoparticles to prevent it from being oxidized?

Standard curve of H2O2?

Non -oxidizing metal binders?

What is the main used curing agent for epoxy based coating?

How to scrape off the surface layer of compound sputtering targets as with multiple usage top layer's stoichiometry changes from the original target?