Complex intermetallic compounds and metal hydrides from powder diffraction
Radovan Černý
Laboratory of Crystallography, University of Geneva
Radovan.Cerny@cryst.unige.ch
Intermetallic compounds are playing important role in many technological applications (high performance construction materials, magnetic materials, hydrogen storage). The characterization of their crystal structure is not an easy task due to often presence of lattice defects, chemical disorder, pseudosymmetry and weak superstructures. The fact that the intermetallic structures do not contain easily recognizable building units like molecules, and that they are often build up from atoms with large scattering contract, does not simplify their structural characterization by diffraction methods either. The single crystals are often not available, and structure size can reach few hundreds of independent atoms.
In the talk we will review the pitfalls of the structural characterization of intermetallic compounds by X-ray and neutron powder diffraction. Different tools of structure characterization of intermetallic compounds and their hydrides like high reciprocal space resolution [1], resonant diffraction [2], in-situ studies [3], methods and programs for structure solution [4] will be discussed with examples from our work.