About short and long range ordering in wüstites, Fe1-xO

This short contribution consists of several comments on a paper recently published by T.R. Welberry and A.G. Christy in Physics and Chemistry of Minerals (volume 24, Number 1, January 1997, pages 24–38). Due to the fact that some of the previous works were not taken into account by these authors, it seems necessary to present briefly a short review of the main results concerning the short and long range ordering of point defects in wüstites Fe_1-xO. Using direct imaging found in the literature, it was clearly shown in papers of our group, from 1981 to 1991, that one of the most probable and numerous clusters in wüstite under equilibrium is the (10/4) one, which is of blende ZnS type. The P' and P'' quenched phases were also described from this cluster.