Martensitic structures and deformation-induced displacive transformations in the compounds ZrIr and ZrRh

Abstract

The compounds ZrIr and ZrRh possess ordered B2-type structures at high temperatures and both undergo a martensitic transformation on cooling. The two low-temperature martensitic phases produce similar x-ray powder diffraction patters which suggested to us that their crystal structures are virtually identical. This structure, however, has never been subjected to a rigorous x-ray diffraction analysis, probably because the available single crystals are too small. The powder diffraction peaks of these compounds are unusually broad and are not sharpened significantly by annealing. This is a report of some preliminary high-temperature thermomechanical experiments on these two compounds and a description of the martensitic crystal structure which was solved from XRD and ND powder data and single-crystal electron diffraction (SAD) data.