Field-temperature phase diagrams of cubic compounds PrPb3 and PrOs4Sb12 with non-magnetic crystalline electric field (CEF) ground state have been examined by means of low-temperature magnetization measurements. PrPb3 is a typical Γ3 doublet CEF ground state system which undergoes an antiferro-quadrupole (AFQ) transition at TQ = 0.4 K. In a magnetic field TQ(H) exhibits re-entrant behaviour depending on the field direction, which can be interpreted in terms of interactions between induced dipole (and possibly octupole) moments in the AFQ phase. In the heavy-electron superconductor PrOs4Sb12, a field-induced ordered state has been observed above 4 T for all the principal directions. The results are in favour of a Γ1 CEF ground state model in which a level crossing with a Γ5 triplet excited state induces a long-range (possibly quadrupolar) ordering in a magnetic field.
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