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Fermi surface properties in rare earth (R) and actinide (An) compounds of RX3 (X: Al, Ga, In, Si, Ge, Sn, Pb), AnX3, RTIn5 (T: transition metal), and AnTGa5 are clarified as a function of the number of valence electrons. The electronic state can be changed by applying pressure and magnetic field. A change of Fermi surface properties associated with the metamagnetic behavior and the quantum critical point is also clarified precisely, together with the split Fermi surfaces in the non-centrosymmetric crystal structure, and the de Haas-van Alphen oscillations in the superconducting mixed state. In the quantum critical point region, the conduction electrons, or quasi-particles, are of an f-electron character, with heavy effective masses of 10-100 m0 (m0 is the rest mass of an electron) and condense into the unconventional (anisotropic) superconducting state. [ABSTRACT FROM AUTHOR]

Abstract: We have carried out the de Haas–van Alphen (dHvA) experiment of an antiferromagnet under pressure. The detected dHvA branches and at ambient pressure are well explained by the corresponding dHvA branches in , indicating that the f electron is localized at ambient pressure. At 2.9GPa, where the antiferromagnetic ordering disappears completely, a new branch appears. This is approximately the same as that of 4f-itinerant Fermi surface in , suggesting that the 4f electronic state is changed into an itinerant one. [Copyright &y& Elsevier]

Abstract: We have measured the de Haas–van Alphen (dHvA) effect in under high pressures up to 3.0GPa, and found that both the dHvA frequency and cyclotron mass of -branch considerably decrease with increasing pressure. [Copyright &y& Elsevier]

Abstract: We have measured the electrical resistivity of antiferromagnetic Kondo compounds and under pressure. In , Néel temperature initially increases with increasing pressure up to 3GPa, then decreases rather steeply with further increasing pressure, and becomes zero at a critical pressure . The and values of the resistivity in the Fermi liquid relation become maximum around . Superconductivity is found below 0.48K in a wide pressure region from 4 to 10GPa. In , the similar pressure dependence of is found, has a maximum at 3.9GPa, and becomes zero around 6GPa. [Copyright &y& Elsevier]

Abstract: We grew a single crystal of an antiferromagnetic CeRhGe and studied the electronic state by measuring the electrical resistivity, magnetic susceptibility, magnetization and neutron scattering. The magnetic susceptibility is found to be highly anisotropic, reflecting the orthorhombic crystal structure. The antiferromagnetic structure is, however, not simple, as expected from the results of the susceptibility. The resistivity peaks at the Néel temperature, which was observed under pressure, is pronounced with increasing pressure up to 1.3–1.5GPa. [Copyright &y& Elsevier]