Suppression of the martensitic phase transition and the effect on superconductivity in HfV2

HfV2 has been classified as a heavy Fermion system with a superconducting ground state characteristic of strong electron phonon coupling. An instability of the lattice at 117 K is believed to significantly influence the onset of superconductivity below ∼9 K. Neutron diffraction and magnetisation measurements carried out on a specimen in which the structural phase transition has been suppressed reveal that the superconducting transition is only slightly reduced to 8.1±0.1 K.