Diffuse scattering in potassium feldspars at high temperatures

We aim to study temperature and cooling-rate dependent local oder phenomena and their influence on the diffuse scattering in the mineral group of potassium feldspar. The potassium feldspars are classified with regard to Si/Al order, from fully ordered microcline, to patrially ordered orthoclase and disordered sanidine. Diffuse scattering in Sanidines has been suggested to be a result of the distorted aluminosilicate framework, where diffuse streaks manifest the strain propagation through the sample due to the different ionic radii of Si and Al. Here we want to investigate possible local order phenomena with regard to composition and initial state of order. For this we want to utilize variable temperature single crystal scattering experiments and different cooling rates, wich provide a unique way of investigating the Si/Al order and resulting strain.