Structural sensitivity of superconducting properties of layered systems

Physics of layered systems is studied from the crystal structure point of view. The relationships between structural and superconducting properties are discussed, and particular attention is paid to the layered structure. We discuss the possible role of inequivalent layers and charge transfer interlayer redistribution. By taking into account the modified charge transfer approach a workable model that provides a possibility for comparison of the structural, electronic, chemical factors etc., for the occurrence of superconductivity of layered systems is considered. The present paper analyzes the possible applications of the inequivalent layer model to the mercurocuprate family and provides rationalization to the experimentally observed nonmonotonic 'bell'-shaped dependence of critical temperature of a number of layers in the elementary cell