The ordering of vacancies in Ni1−xAl study of the transition state by electron diffraction

After suitable heat treatment the structural vacancies in non-stoichiometric Ni1−xAl show a degree of order which is intermediate between short range and long range order. The ordering state, called transition state, is described by means of predominant characteristic clusters. It is shown that in the transition state a structural property of the long range order state is conserved.