  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, and a first-order spin reorientation transition
at T*. 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.
