Re: [Ifeffit] UO2 thin films on STO

I'm assuming that the desire is to measure the EXAFS of the UO2, not the SrTiO3 substratem right? The ratio of the signal from the SrTiO3 to the UO2 would depend on the thickness of the UO2 and the incidence and takeoff angle (assuming you do fluorescence). There shouldn't be much interference with the EXAFS signal from the substrate because you're a keV away, so the EXAFS from the substrate will be substatially damped and will show up as slowly-varying background. The real issue will be if the fluorescence from the Sr swamps that of the U. The fluorescence energies are pretty close. Some things to try include going to grazing exit or incidence, depending on the film thickness, and doing the measurement in electron yield, which won't see much of the substrate. mam On 11/16/2010 2:16 PM, María Elena Montero Cabrera wrote:

Dear Mohamed, I think you will have some kind of "over" or "self" -absorption from the substrate, specially in geometries other than grazing incidence. I have performed that kind of experiments in fluorescence and in transmission. The result was that the absorption coefficient signal I was interested in, really was of 2nd or 3rd order of magnitud less that the "tail" of absorption of the substrate. I would not do that again. Maybe somebody has better experience. Regards Maria Elena

2010/11/16 mohamed sobhy mailto:bakhshwan1981@yahoo.com>

Dear All I would like to grow UO2 thin films on STO (SrTiO3) substrate but I found that Sr K-edge 16105 and U L3-edge is 17166. Do you think there will be any interference? Best,

Mohamed

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-- María Elena

Dra. María Elena Montero Cabrera Centro de Investigación en Materiales Avanzados (CIMAV) Miguel de Cervantes 120, Compl. Ind. Chihuahua Chihuahua CP 31109, Chih. México Tel (614) 4391123

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