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The de Haas–van Alphen effect, which is a powerful method to explore Fermi surface properties, has been observed in cerium, uranium, and nowadays even in neptunium and plutonium compounds. Here, we present the results of several studies concerning the Fermi surface properties of the heavy fermion superconductors UPt 3 and NpPd 5 Al 2 , and of the ferromagnetic pressure-induced superconductor UGe 2 , together with those of some related compounds for which fascinating anisotropic superconductivity, magnetism, and heavy fermion behavior has been observed. [ABSTRACT FROM AUTHOR]

We present an overview of the Fermi-surface properties for antiferromagnets CeRh2Si2, CeIn3, CeRhIn5, and CeIrSi3, which were clarified from the de Haas-van Alphen (dHvA) experiments under strong magnetic fields up to 170 kOe and high pressures up to 3 GPa. A drastic change of the 4f-electronic state from a 4f-localized Fermi surface to a 4f-itinerant Fermi surface occurs in CeRh2Si2, CeIn3, and CeRhIn5 when the pressure P crosses a critical pressure Pc or $P_{{\rm c}}^{*} $. Here, the Néel temperature TN disappears and the superconducting state appears at around Pc or $P_{{\rm c}}^{*} $. A critical pressure $P_{{\rm c}}^{*} $ in CeRhIn5 is the pressure when TN is extrapolated to zero in the temperature vs. pressure phase diagram, and/or the antiferromagnetic state disappears completely even in magnetic fields. This is because the antiferromagnetic state is stable against magnetic fields, or in other words, the antiferromagnetic state recovers in magnetic fields. CeIrSi3 without inversion symmetry in the tetragonal structure is also similar to CeRhIn5 in the superconducting and Fermi-surface properties. It is characteristic that a huge upper critical field at zero temperature in superconductivity $H_{{\rm c2}} (0) \simeq 450\,{\rm kOe}$ is realized for $H{\parallel} [001]$ in CeIrSi3 with the superconducting transition temperature Tsc = 1.6 K. [ABSTRACT FROM AUTHOR]

We carried out the de Haas-van Alphen (dHvA) experiment for an antiferromagnet UCd11 and its non-5f reference compound ThCd11 to clarify the Fermi surface properties and the true electronic specific-heat coefficient γ of UCd11. We observed dHvA signals of both compounds and compared the experimental results with the result of theoretical band calculations. The Fermi surfaces of both compounds are found to be small and closed. The cyclotron masses obtained from the dHvA data of UCd11 are compared with those of reference compounds ThCd11, NpCd11, and LaCd11, and the γ value of UCd11 is estimated to be about 100 mJ K−2 mol−1, which is much smaller than the 840 mJ K−2 mol−1 in the previous reports. It is concluded that this large value is mainly not due to heavy quasiparticles but due to the magnetic contribution to the specific heat. [ABSTRACT FROM AUTHOR]

We present the quasi-two-dimensional Fermi surface studies in RTIn5 (R: rare earth, T: Co, Rh and Ir), together with UTGa5. The present quasi-two dimensionality is closely related to the unique crystal structure elongated along the [0 0 1] direction, which brings about a flat Brillouin zone and produces cylindrical but highly corrugated Fermi surfaces along [0 0 1]. [Copyright &y& Elsevier]

Abstract: We grew high-quality single crystals of and succeeded in observing the de Haas–van Alphen effect. The metamagnetic transition, where the antiferromagnetic state changes into the paramagnetic (field-induced ferromagnetic) state, was observed at for . On increasing the field angle , follows the dependence, indicating an Ising-type antiferromagnet. The main Fermi surface in consists of two kinds of cylindrical ones. The detected cyclotron effective mass is considerably large, ranging from to in the paramagnetic state. is a heavy-fermion compound and the 5f electrons significantly contribute to the conduction bands. [Copyright &y& Elsevier]

Abstract: The topology of the Fermi surface in CePt3Si is most likely similar to that in LaPt3Si. In fact, one small Fermi surface in CePt3Si is the same as that in LaPt3Si, where the main Fermi surface in LaPt3Si consists of three-dimensional multiply-connected Fermi surfaces. With increasing pressure, the topology of the Fermi surface in CePt3Si is approximately unchanged but the cyclotron effective mass is found to be reduced, together with a steep decrease of the Néel temperature and superconducting transition temperature. These results indicate that the heavy fermion state in CePt3Si, which is closely correlated with superconductivity, is stable at ambient pressure. [Copyright &y& Elsevier]

Abstract: We measured the magnetic susceptibility and magnetization of an antiferromagnet Ce3Sn7 with the orthorhombic crystal structure. The experimental data are found to be well explained on the basis of the crystalline electric field (CEF) 4f-scheme under the assumption that two Ce atoms in the 2(a) site possess a magnetic moment of and one Ce atom in the 4(i) site possesses no magnetic moment as in a valence fluctuating compound CeSn3, which was previously proposed by Bonnet et al. Furthermore, we carried out the de Haas–van Alphen experiment. The detected Fermi surfaces are many in number but are extremely small in volume, indicating that Ce3Sn7 is a semimetal. [Copyright &y& Elsevier]

In order to investigate the magnetic structure and Fermi surface properties of UNiGa5, we have performed elastic neutron scattering and de Haas-van Alphen(dHvA) experiments. In the neutron scattering experiment using a single crystalline sample, we determined the antiferromagnetic propagation vector Q=(1/2,1/2,1/2) in UNiGa5. In the dHvA experiment, we observed four branches. Two branches indicate cylindrical Fermi surface and the other two branches correspond to ellipsoidal ones. The cyclotron mass was not large, ranging from 1.3 to 3.1m0. [Copyright &y& Elsevier]

The angular dependence of de Haas–van Alphen effect has been measured to reveal the electronic structure of filled skutterudite PrRu4Sb12. The angular dependence of de Haas–van Alphen frequency of PrRu4Sb12 is in good agreement with that of LaRu4Sb12. Compared with PrFe4P12, no anomalous enhancement of cyclotron effective mass has been observed in this system. This change of electronic structure is attributed to the difference in the c−f hybridization strength, which is expected from the large difference in the lattice parameters. [Copyright &y& Elsevier]