  Single crystalline samples of the van der Waals antiferromagnet CrPS4 were
studied by measurements of specific heat and comprehensive anisotropic
temperature- and magnetic field-dependent magnetization. In addition,
measurements of the heat capacity and magnetization were performed under
pressures of up to ~21 kbar and ~14 kbar respectively. At ambient pressure, two
magnetic transitions are observed, second order from a paramagnetic to an
antiferromagnetic state at TN ~ 37 K, and a first-order spin reorientation
transition at T* ~ 34 K. Anisotropic H - T phase diagrams were constructed
using the M(T,H) data. As pressure is increased, TN is weakly suppressed with
dTN/dP ~ -0.1 K/kbar. T*, on the other hand, is suppressed quite rapidly, with
dT*/dP ~ -2 K/kbar, extrapolating to a possible quantum phase transition at Pc
~ 15 kbar.
