Search for Sublattice Distortion inV3Si

Abstract

We have attempted to find x-ray reflections in the low-temperature tetragonal form of ${\mathrm{V}}_3$Si, normally forbidden in the cubic phase, which would indicate a distortion of the vanadium or silicon sublattices. The results are negative and allow us to quote an upper bound on the possible distortions predicted by symmetry considerations. In the Appendix, one of the authors (E.I.B.) has elaborated on the group-theory arguments of Anderson and Blount, giving the predicted tetragonal symmetries consistent with Landau's theory of second-order phase transformations.