О возможных состояниях кристаллической структуры, предшествующих фазовому переходу в кристаллах Zn-=SUB=-1-x-=/SUB=-V-=SUB=-x-=/SUB=-Se (0.01≤ x≤0.10)

The systematic new formations observed in the reciprocal lattice of the cubic structural modification of a II–VI compound are characterized using a detailed neutron diffraction study of bulk semiconducting ZnSe crystals with an increased vanadium content. Direct evidence that the additional sites k = (1/3 1/3 1/3) 2π/ a ( k is the wave vector and a is cubic unit cell parameter) observed by neutron scattering in the crystals, in the case when they belong to mutually penetrated rotated sublattices, contain a superstructure contribution formed by short-wave deformation, is obtained for the first time. This structure state is determined as a pretransition to the concentration fcc–hcp phase transformation, and the basis functions that allow one to analyze atomic displacements, the correlation between which create distortion-type superstructures, are indicated for the transition through one-arm channel, considering the transitions by the star of wave vector k _5 of the fcc lattice.