Dear Arnt i have worked with old x-ray diffractometers ( siemens d500 and d5000)and the instrumental profile starts from a gaussian content to lorentzian, but usually the eta value is less 0.5, and recently I worked with a Bruker D8, Theta -Theta geometry and the values of eta are from 0.5 and more, in principle i thougth that something was wrong in the equipment, but how can we explain the diferences?, and how can we related this fact with the determination of crystallite size and microstrain if we consider that the instrumental contribution is mainly gaussian ? i would like to obtain a copy of the paper that you have commented.
Thanks a lot Miguel Hesiquio-Gardu�o Departamento de ciencia de materiales ESFM-IPN, Mexico
