  The ground state of URu2Si2 changes from so-called hidden order (HO) to
large-moment antiferromagnetism (LMAF) upon applying hydrostatic pressure in
excess of 14 kbar. We report the dc-magnetization M(B,T,p) of URu2Si2 for
magnetic fields B up to 12 T, temperatures T in the range 2 to 100 K, and
pressure p up to 17 kbar. Remarkably, characteristic scales such as the
coherence temperature T*, the transition temperature T0, and the anisotropy in
the magnetization depend only weakly on the applied pressure. However, the
discontinuity in dM/dT at T0, which measures the magnetocaloric effect,
decreases nearly 50 % upon applying 17 kbar for M and B parallel to the
tetragonal c-axis, while it increases 15-fold for the a-axis. Our findings
suggest that the HO and LMAF phases have an astonishing degree of similarity in
their physical properties, but a key difference is the magnetocaloric effect
near T0 in the basal plane.
