Probing Magnetism in CePdAl under Multi-Extreme Conditions using Polarized Neutrons

We have performed polarized neutron experiments on single-crystalline CePdAl at two different conditions: at 4 K and ambient pressure in a field of 9 T applied along the c-axis and at 40 mK under a pressure of 0.85 GPa and the same magnetic field. We observe that in contrast to zero field, where only two Ce atoms carry magnetic moments, in fields under different conditions all Ce moments are significantly developed. Thus, the magnetic field lifts the magnetic frustration caused by the geometry of the system. It also eliminates effects of the pressure that drives CePdAl to a quantum criticality and loss of long-range magnetic order.