Low-temperature magnetization study on the non-kramers cubic system Pr ₃Pd₂₀Ge₆

We report on high-precision magnetization measurements on the non-Kramers cubic compound Pr₃Pd₂₀Ge₆, for temperatures down to ∼ 80 mK, in fields applied parallel to the [100] and [110] directions up to 8.5 T. Multistep-like structures of the magnetization curves are found below about 1 K for both the field directions. Temperature variations of the magnetic susceptibility show no tendency to saturate down to 80 mK, implying that the crystalline-electric-field (CEF) lowest state of 4f electrons for at least one of the Pr sites is the magnetic triplet γ₅. No significant anomaly is observed at 0.26 K, where quadrupole order is suggested from ultrasonic sound velocity measurements. An application of a simple CEF model is discussed.