The thermal conductivity of the heavy fermion superconductor UPt3 has been measured as a function of magnetic field in a single crystal for a heat current along the c-axis. It is found to depend strongly on the relative orientation of current and field. Moreover for a field in the basal plane, anomalies are observed along a line in (H-T) plane where anomalies in ultrasonic attenuation have been reported. © 1990.

Specific heat (C) measurements in magnetic field (H) up to 8 T show drastic changes below the superconducting transition in contrast to the H independent value of C T in the normal phase. It is suggested that the normal phase may undergo magnetic order at T ∼ 150 mK. © 1988.

Measurements of the resistivity, thermoelectric power and thermal conductivity of the heavy fermion compound UBe//1//3 and their relations to the temperature-upper critical field phase diagram are reported. At low temperature (T less than 1 K), enormous thermoelectric powers are detected in the normal phase. The thermal conductivity obeys a T**2 law in the superconducting phase with no supplementary T contribution which is not observed in the other heavy fermion compound UPt//3.

The linear magnetostriction (λ{norm of matrix} and λ⊥) of a single-crystalline sample of the heavy-fermion compound UBe13 has been measured for fields B < 8 T (B{norm of matrix}[100]) in the temperature interval 0.3 < T < 12 K. We find neither evidence for the antiferromagnetic order (TN = 8.8 K) nor for the magnetostrictive oscillations, that were reported recently. Instead λ varies proportional to B2 as expected for a normal paramagnetic metal. © 1992.

The linear magnetostriction () and the coefficient of linear thermal expansion (±) of a single-crystalline sample of the heavy-fermion compound UBe13 have been determined for elongation directions along and perpendicular to the applied magnetic field (B[100]), in the temperature interval 0.3

The thermal conductivity κ of the heavy-fermion superconductor UPt3 has been measured on two single crystals of different quality as a function of temperature and applied magnetic field for different orientations of the heat current relative to both the field and the crystalline axes. The temperature dependence of κ is far from exponential and nearly the same for both crystals, in which the heat current is, respectively, parallel and perpendicular to the hexagonal c axis, suggesting a gap structure with nodes in the basal plane and normal to it. The field dependence of κ is strongly anisotropic. In the best sample at low fields, where the scattering of heat carriers by vortices is thought to be important, κ(H) depends on the relative orientation of field and current. On the other hand, at high fields near Hc2 (in both samples), κ(H) depends on the relative orientation of field and crystalline axes, reflecting an anisotropy in the gap structure and in the Fermi velocities. © 1991 Plenum Publishing Corporation.

Transport and specific heat measurements are reported on a new sample of UBe13. Special focuses are given on the zero field specific heat : at low temperature (T < 150 mK) where the impurity scattering dominates, at intermediate temperature where a quasi T3 law characteristic of an axial state is obeyed and near the critical temperature where critical fluctuations are observed. Correlations are made with magnetoresistivity and thermal conductivity experiments. © 1988.

Low temperature magnetoresistivity of UBe13 shows that the interactions between heavy fermions are field dependent. This suggests a field variation of the superconducting condensation energy. The Hall resistivity is strongly nonlinear in magnetic field. © 1988.