I’m trying to calculate the penetration dept of the X-ray beam in my perovskite sample depending on the incidence angle. I found a tool (http://www.ccp14.ac.uk/ccp/web-mirrors/bca-spreadsheets/xrdpenetr.xls) to calculate this for my materials, but the MAC value for Iodine is missing. I performed my XRD measurements using a Cu Kα1-radiation (λ = 1.5406 Å) source.
I tried to take the mu/rho value from NIST (http://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z53.html), but it looks like I shouldn’t take the value at around 8 keV (at least this doesn't match the numbers for other elements that are already in the table)
Can someone tell me what the MAC value for iodine is in this case and how to obtain this number.
http://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z53.html
http://www.ccp14.ac.uk/ccp/web-mirrors/bca-spreadsheets/xrdpenetr.xls
Hi Michiel, please take the u/r [cm²/g] value from the NIST table. In addition you have to multiply this value with the density r [g/cm³]of the Iodine in your sample, so you get the linear attenuation coefficient u [1/cm]. 1/u [cm] then is your penetration depth. But for the case of your perovskite sample, you have to pay attention to the other elements in your sample. You have to add all the u's of the different elements in your sample and take 1/u.
Hi Michiel; I have cross-checked the u/r value of NIST with other sources (e.g. CRC Handbook of Spectroscopy). The u/r Iodine value of the NIST table at 8keV is ok (292,2cm²/g). Please take in account the incident angle when calculating your penetration depth. Refraction of the x-ray beam has to be considered only when you are around the critical angle of total reflection.
According to the ICDD table the mass attenuation coefficient for CuKalpha radiation for Iodine is 294 cm2/g.
Best regards,
Pedro
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