Systematics and optimisation of hole doping in Bi-2223

We report systematic changes in thermopower, T-c, Raman modes and magnetic irreversibility Hi,, as a function of carrier hole concentration p in Bi-22 23. We have established that Raman spectroscopy can provide an indicator of doping level: the 630cm(-1) mode is found to soften with increasing p. A d eparture of the thermopower from the universal thermopower-doping relations hip displayed by other HTS compounds is explained by a non-uniform charge d istribution over the three CuO2 planes. Scaling of H-irr shows the optimal hole concentration for maximum J(c) lies beyond currently achieved levels.