A polarized neutron investigation of the martensitic phase transition in V3Si: evidence for a band Jahn–Teller mechanism

Polarized neutron diffraction has been used to study the structural phase transition in V3Si. The redistribution of electrons between the two independent Vsites in the low-temperature phase ofV3Si has been determined by comparing the magnetic scattering observed from reflections that are equivalent in the high-temperature cubic phase but inequivalent below the transition. The higher susceptibility observed at the twofold, compared with the fourfold, vanadium sites in the tetragonal phase is consistent with the predictions of a band Jahn– Teller model of the phase transition.