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We measured the electrical resistivity of a prototype heavy fermion antiferromagnet CeAl 3 in the temperature range from 0.1 K to room temperature under various magnetic fields and pressures. The heavy fermion state at ambient pressure is drastically destroyed under a small pressure and magnetic field.

We measured the electrical resistivity, magnetic susceptibility, and specific heat in quasicrystal approximants RCd 6 . It was confirmed that the structural order–disorder transition of a tetrahedron with 4Cd atoms occurs at about 160 K when the lattice constant a is longer than a = 15.481 A in YCd 6 , namely for RCd 6 (R: Y, Pr, Nd, Sm, Gd, Tb, Dy, and Yb ). The structural transition is found to have a great influence on the low-temperature electrical resistivity.

The enhancement ofTc in Pb-Bi-Sn and Pb-Bi-In system alloy filaments produced by glass-coated melt spinning was investigated as a means of producing a new type of superconducting filament with highTc. Long filaments of Pb-Bi-Sn alloy withTc higher than 10 K and Pb-Bi-In alloy withTc higher than 9 K were obtained from the molten state at a temperature of 1500 K with a winding speed of 2.63 m sec−1. For example, a Pb45Bi35Sn20 filament withTc of 10.1 K was 15 μm in diameter and polycrystalline with a grain size of 100 nm. The structure of the filament was a mixture of ɛ, tin and bismuth phases and a metastable phase of mixed structure of bismuth and supersaturated solid solution of tin in ɛ-phase was detected. TheTc of the filament decreased on heat treatment. A metastable phase of mixed structure of bismuth and ɛ-phase was also detected for a Pb45Bi45In10 filament withTc of 9.3 K. As the metastable phase for the Pb-Bi-In filament was more unstable than that for the Pb-Bi-Sn filament, theTc of the filament was drastically decreased by heat treatment. The metastable phase was considered to play an important role in the enhancement ofTc for Pb-Bi-Sn and Pb-Bi-In alloy filaments.