X-ray absorption spectroscopy - fine edge structure

[lavster]

Hi,

could someone tell me how the fine edge structure next the the absorbing edge in an XAS arises? from my understanding an XAS is a plot of absorption coefficient against energy of incoming xray. The absorption edge is at an energy corresponding to when the energy is just sufficient to excite an electron from the core shell to the vacuum. The fine edge structure is then somehting to do with the photoelectron wave but i didnt understand what i says in the literature...

Thanks

 

[Rajini]

Hi,

I guess it should be due to photoelectron, which leaves are scattered again by neighbouring atoms.

 

[lavster]

but why/how does this make any difference to the absorption coefficient of the material?!