ABSTRACT
The doping phase diagram brings out the extreme importance of controlling and measuring the hole concentration in cuprate superconductors. Oxygen content is usually measured by thermogravimetric analysis. In both bulk materials and thin films the control of oxygen concentration is not easy. In considering the transition in the cuprates from the afm state to the metallic state with increasing hole concentration, it is important to consider what happens to the local magnetic moments. The afm state itself has a typical three-dimensional antiferromagnetic arrangement of localized spins on the Cu atoms of the CuO2 planes. Outside the CuO2 planes we may treat the cuprates as fully ionic, with the electrons on the ions in tightly bound localized states which are far from the Fermi energy: they have a negligible role in the electron dynamics, except as dopants.
