[en] The authors have measured the superconducting transition temperature from ac susceptibility measurements in isotopically pure samples of ⁶LiTi₂O₄ and ⁷LiTi₂O₄. The transition temperature and transition widths are found to be identical for the two samples. Past measurements on this compound show it to be a d band coupling BCS superconductor involving the Ti-O network in the spinel structure. However, it is surprising that the high energy phonons due to the Li vibrations have absolutely no effect on the superconducting transition temperature in that the normal state conductivity is dominated by the Li concentration with a metal insulator transition occurring as a function of Li doping

No abstract available

No abstract available

[en] Measurements of the de Haas-van Alphen effect have been carried out on the heavy fermion anti-ferromagnet CeRhIn₅ at temperatures between 25 and 500 mK under pressure. We present some preliminary results of our measurements to track the evolution of the Fermi surface as the pressure induced superconducting transition is approached

[en] Results are presented on measurements of the magnetization of the heavy fermion superconductor CeIrIn₅ at 45 mK and DC magnetic fields up to 45 T. A metamagnetic transition is clearly seen at 29.5 T that is qualitatively similar to metamagnetic transitions reported by other groups. In addition, we also find a second magnetic transition at higher fields that exhibits significant hysteresis and has a pronounced ferromagnetic-like character that has not previously been observed in CeIrIn₅

[en] A review is given of the general types of experiments that can be performed to distinguish between broad classes of theories of superconductivity. It is concluded that this distinction will be very difficult for all theories that are similar to Bardeen, Cooper and Schriefer (BCS) but with a different interaction causing the pairing. Theories that start from a correlated normal state should give significantly different results from experiments

[en] The Fermi surface of rhenium has been determined from radiofrequency size effect measurements. Fermi surface arising from holes in the fifth, sixth and seventh bands and electrons in the eighth band are topologically described. It is concluded that a previously described ninth band electron surface does not exist and that all previous data ascribed to it can be assigned to other portions of the Fermi surface. (author)

[en] Results of parallel-field, radio-frequency, size-effect measurements are presented. A T² dependence of the line amplitude is observed and extensive Fermi-surface dimensions are determined. (author)

[en] The temperature dependence of several RFSE signals in rhenium which correspond to different orbits on one piece of the Fermi surface of the metal has been measured. The data suggest that the electron-electron interaction for electrons on this piece of the Fermi surface is isotropic within experimental uncertainty whilst the strength of the scattering of the electrons by photons is a strong function of their position on the Fermi surface. (author)

[en] RF impedance measurements were performed on YBa₂Cu₃O₇. They are analyzed on the basis of 2-dimensional conduction