Hello. I am a PhD student and need your help. I am currently investigating the structure of an aluminosilicate with boron substituted for aluminium by X-ray diffraction. Using Rietveld refinement, I am trying to determine the respective positions of the boron and aluminium sites within the structure, as well as their occupancies, and to follow the structural evolutions when the boron content increases. Unfortunately, there seems not to be any tabulated scattering factor for B+3, neither in the refinement softwares (I use Fullprof) nor in the International tables for X-ray crystallography?
Could someone tell me what the correct procedure for my study would be? I first tried to define all the atoms as neutral and I am quite happy with the fit obtained. But this does not really sound true. Should I better use Al3+, Si4+, O2- and Be2+ (same electron number than B3+ but probably not the same sin/theta*lambda evolution) ? Thanks for your help. Emmanuel Véron CEMHTI-CNRS Orléans-FRANCE ****************************************** Emmanuel Veron CNRS - CEMHTI Tel. 02.38.25.55.32 Mail ve...@cnrs-orleans.fr ******************************************
