High-quality single crystal growth and unique electronic states under magnetic field and pressure in rare earth and actinide compounds

The f electrons in rare earth and actinide compounds exhibit variety of characteristic properties including heavy fermions and unconventional superconductivity. Fermi surface properties in rare earth and actinide compounds such as CeSn₃, USi₃, NpGe₃ and PuIn ₃ are clarified by the de Haas-van Alphen experiments on the basis of the results of energy band calculations. An abrupt nonlinear increase of magnetization, namely metamagnetic behavior is found in the heavy fermion compounds including YbT₂Zn₂₀ (T: Co, Rh, Ir). An effect of pressure on the electronic state of YbIr₂Zn₂₀ and antiferromagnets CeRhIn₅ and CeIrSi₃ are also studied in magnetic fields. The electronic instability including unconventional superconductivity occurs at about 2.4 GPa in CeRhIn₅ and 2.6 GPa in CeIrSi₃.