NEUTRON-DIFFRACTION STUDY OF ATOMIC ORDERING IN THE ALLOYS OF PSEUDOBINARY SECTION OF NIAL - FEAL AND NIAL - COAL SYSTEMS

Due to X-ray-diffraction and neutron-diffraction analyses of ternary i ntermetallic compounds belonging to the pseudobinary section NiAl - Co Al, it was established that one sublattice is occupied by only aluminu m atoms and another sublattice is occupied by randomly distributed Ni and Co atoms. The experimental results are adequately described by a m odel of random distribution of Ni and Fe atoms in one sublattice. No s hort-range order is revealed in (Ni,Fe) and (Ni,Co) sublattices.