Phase diagram of URu Fe Si in high magnetic fields.

Electrical transport measurements were performed on URu Fe Si single-crystal specimens in high magnetic fields up to 45 T (DC fields) and 60 T (pulsed fields). We observed a systematic evolution of the critical fields for both the hidden-order (HO) and large-moment antiferromagnetic (LMAFM) phases and established the 3D phase diagram of In the HO phase, / scales with / and collapses onto a single curve. However, in the LMAFM phase, this single scaling relation is not satisfied. Within a certain range of values, the HO phase reenters after the LMAFM phase is suppressed by the magnetic field, similar to the behavior observed for URuSi within a certain range of pressures.