Pressure dependence of the magnetic transition fields of the quasi two-dimensional antiferromagnet (C2H5NH3)2 CuCℓ4

Using magnetic susceptibility measurements, we have studied the pressure dependence of the magnetic transition fields of powder samples of antiferromagnetic (C₂H₅NH₃)₂CuC?₄, for hydrostatic pressures up to P ～ 7 kbar. The spin-flop field H₁ decreases linearly with pressure $\text{(}\text{dH}{}_1\text{dP}\text{= ?(20±4)}\text{G}\text{kbar}\text{)}$, while the field corresponding to the paramagnetic transition H₂ shows an increase, ～ 70% for P～7 kbar, that is roughly quadratic with P.