Electronic phase transition and superconductivity of vanadium under high pressure

Abstract

We report a theoretical calculation of the electronic band structure, density of states, phase transitions, and superconductivity of vanadium under pressure. The total energies of vanadium corresponding to bcc, fcc, simple cubic (sc), and simple hexagonal structures are computed. From the enthalpy calculation, it is found that up to ${V/V}_{0}=0.685$ vanadium has the bcc structure and a further increase of pressure induces a structural phase transition from bcc to sc structure. Under normal conditions, the superconducting transition of vanadium occurs at 5.97 K ${(T}_{c}).$ When the pressure is increased it is predicted that ${T}_{c}$ increases at a rate of 10.78 K/Mbar for pressures up to 1.393 Mbar, whereas the experimental increase is 9.6 K/Mbar for pressures up to 1.20 Mbar. The highest ${T}_{c}$ estimated is 20.99 K and the corressponding pressure is 1.393 Mbar. On further increase of pressure ${T}_{c}$ begins to decrease at a rate of 1.42 K/Mbar in bcc structure and 0.2355 K/Mbar in sc structure. Experimental evidence is available up to the 1.2 Mbar pressure region.