Low Temperature Magnetic Properties of Ce3Pd20Si6

This is the authors' abstract. We don't add key points for this paper.

Magnetization of a single crystalline Ce 3 Pd 20 Si 6 was measured at low temperatures down to 90 mK in fields up to 11 T for the three principal directions [100], [110], and [111]. For all directions, two transitions were observed in the temperature variation of the magnetization M ( T ) at 0.2 T; a broad peak at 0.28 K associated with a phase-III transition, and an upward bending at ∼0.5 K due to a phase-II ordering from the paramagnetic state (phase-I). The latter critical temperature T I–II is found to be strongly enhanced in magnetic fields B , depending on the field direction, and T I–II ( B ) becomes highly anisotropic. These results suggest that phase-II is an antiferroquadrupole state originated from a Γ 8 ground state. By contrast, no appreciable anisotropy is found in the phase-III state. At 90 mK, phase-III collapses by applying a field of ∼0.63 T for all directions. Above this field, the magnetization curve M ( B ) becomes strongly anisotropic. The magnetization value per Ce in the phase-I region at 90 mK is apparently smaller than the Γ 8 moment, indicating that either 8c or 4a site has a Γ 7 ground state.