Focusing High-Resolution Three-Axis Neutron Diffractometer for Investigations of Special Tasks of Powder Diffractometry

Abstract

Feasibility of focusing high-resolution three-axis diffractometer with the polycrystalline sample between the monochromator and the analyzer was tested for studies of finer effects of powder diffraction lines and for investigations of special tasks of powder diffractometry. The focusing 3-axis diffractometer set-up equipped with bent perfect crystal monochromator and analyzer offers the sensitivity in determination e.g. of strains in polycrystalline materials ε =Δd/d close to 10-5. Together with special tasks of strain/stress studies related namely, to plastic deformation, it permits to study a finer substructure of individual diffraction lines which can appear e.g. in case of polycrystalline alloys where more phases having very close values of the lattice spacing could exist. Resolution properties of the high-resolution diffractometer setting will be documented on several experimental results obtained on unconventional bulk samples.