Hi Nelson,
The X-ray atomic form factor has a propotion which changes with wavelegnth. So do not apply the relative intensities in Cu radiation in the NIST Certificate on your mearement in Co radiation. Even you simulate a corundum pattern from a Rietveld code under Co radiation, it will be different to your actural measurement, becasue the NIST 1976b has obvious preferred orientation. Maybe you can parameterise the preferred orientation levels from Cu data, by using a very aggressive model, like spherical harmonics, to achieve best fitting, then simulate a Co pattern after fixing the preferred orientation model. But even though, I think it will be less accurate than just measure it on a well aligned Co machine, which usually has been done in vendor's factories. Cheers! -- Yours Sincerely, Dr. Xiaodong(Tony) Wang At 2017-08-21 00:29:26, "Nelson Duarte" <nelson.dua...@ipn.pt> wrote: >Dear Rietvelders >Iam starting to use NIST standard reference material 1976b for >calibration of line position and intensity as a function of 2theta. >The intensity values of certificate are obtained in a cupper radiation. >I use cobalt radiation. I correct the polarization effect . > >It is necessary apply any additional bias (effect of radiation) to >correct intensity values ? > >Thank you from advance >Nelson > >
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