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By making use of a 15 mm cubic anvil apparatus, Al–Si alloys of Si-concentration up to 15 at% were studied at a pressure of 54 kbar. The liquidus, solidus and solvus of the Al-rich alloys were determined by means of the 4-probe electric resistance measurement. The solubility limit of Si in Al was extended beyond 15 at% at 54 kbar in comparison with 1.59 at% at 0 kbar. The resistivity of the alloy was increased by a solution of Si with a gradient of 0.5 µΩcm/at% up to 15 at%Si. The alloy quenched under high pressure was examined by X-ray diffractometry showing that Si was completely solid-dissolved in Al. The quenched alloy was much more hardened than the ordinary two-phase alloy at 0 kbar.

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We determined anisotropies of superconducting properties of high-T c superconductors, (Cu,V)Sr 2 Ca n−1 Cu n O 2n+3 [(Cu,V)-12(n − 1)n; n = 3, 4]. The samples were grain aligned under a high magnetic field of 7 T. Two kinds of magnetic hysteresis data, one with the magnetic field parallel to the c-axis ( M ) and the other with the magnetic field perpendicular to the c-axis ( M ⊥ ), were measured for the aligned samples. In both phases, the anisotropy factors R = ( M )/( M ⊥ ) decrease to values less than unity with increasing temperature and increasing magnetic field, i.e., M < M ⊥ for a high temperature and/or high magnetic field region. Two sets of values were calculated for critical current density and irreversibility field, corresponding to M and M ⊥ . Anisotropies of these properties are discussed in terms of vortex structures with the magnetic field parallel and perpendicular to the c-axis.

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