How to qualify an homemade standard

[ricounet67]

Hi,
I want to make a Fe90Al10 (wt%) standard. In the lab, we synthetized a Fe90Al10 alloy. We checked by X-Ray diffraction that the sample is pure, the BSE images doesn't show any second phase. I analysed the sample by EPMA by using pure Fe and Cu90Al10 standards and the mean values are close to the expected values and the average sum is 99.837%. Before using it as a standard, I want to be sure if the homogeneity is good enough and what composition I should use.
Do you have any experience on testing a standard ?
Thank you
Best regards,
Eric

[Doug_Meier]

Eric,

I'd use the procedure found within the following article by Marinenko and Leigh:

https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/heterogeneity-evaluation-of-research-materials-for-microanalysis-standards-certification/C029A42EAD98F2DF18343DD6575A5873

This method also appears in ISO 14595, "Microbeam analysis — Electron probe microanalysis — Guidelines for the specification of certified reference materials (CRMs)".

Regards,

Doug