Simultaneous measurements of the d.c. magnetization M(H,T,O) and resistance R(H,T,O) will be performed on monocrystalline samples of a series of superconductors of increasing anisotropy, in order to 1) separate the dissipative contributions from the truly superconducting properties in a dtermination of the upper critical field, and 2) investigate the role of quasi-two dimensionality (anisotropy) with regard to critical temperatures, fields and currents. The systems studied shall be the Bi-and Tl-based oxide superconductors, and the high Tc organic superconductor (BEDT- TTF)2Cu(NCS)2, a closely related and important system which possesses similar flux-flow and anisotropic properties as the oxides.
