Properties of the new high T/sub c/ materials: an analysis based on fermiology

A small value of the Fermi energy, E/sub f/, in the new high T/sub c/ oxides and its consequences are the subject of this study. It is shown that the small value of E/sub f/ allows separation of the electronic contribution to the heat capacity in the high-temperature region E/sub f/k/sub B/>T> theta /sub D/ to determine the value of the electron-phonon coupling constant lambda . The linear temperature dependence of the normal resistance is mainly due to a large anisotropy of the system. A small value of E/sub f/ allows the lattice contribution to the thermal conductivity to play a dominant role. A strong electron-phonon coupling is manifested in the increase of the thermal conductivity in the region T>