Quantum tuning of magnetic phases in vanadium sulphide single crystals

Strongly correlated electron systems are known to host a variety of exotic phenomena and novel quantum phases. The transition-metal chalcogenide system, V_xS₈, is of particular interest, for it displays a wide range of behaviour on changing the stoichiometry, from a charge density wave metal (x=4) to an antiferromagnetic metal (x=5,6) and even, a paramagnet metal (x=8). Here, we focus on V₅S₈, showing how magnetic interactions between the vanadium d-electrons lead to an antiferromagnetic phase below 32K. We present high pressure resistivity data helping to shed light on whether the magnetic electrons are localized or itinerant. Heat capacity measurements up to 14T, reveal an intriguing T² dependence below T_N and down to low temperatures, as well as evidence for new magnetic phases at fields above the 4.5T spin-flop transition.