Substitution effects in magnetic and superconducting materials

Chemical substitutions at very low level have been proved to be a very effective tool to change important physical parameters in many kinds of materials. These modifications may be the result of, for instance, subtle variations of the position of the Fermi level with respect to the density of states...

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Detalles Bibliográficos
Autor: Peña, Octavio
Tipo de recurso: artículo
Fecha de publicación:1999
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::b02c2a1ef05d63777c24b6a9d6e89a61
Acceso en línea:http://hdl.handle.net/10261/51818
Access Level:acceso abierto
Palabra clave:substitution effects
phase transitions superconductivity
Descripción
Sumario:Chemical substitutions at very low level have been proved to be a very effective tool to change important physical parameters in many kinds of materials. These modifications may be the result of, for instance, subtle variations of the position of the Fermi level with respect to the density of states, presence of additional electrons which may change the hole carrier concentration, steric effects which impose contraints in the crystallographic lattice, mixed-valence states resultating from the dismutation of chemical components, etc. We review herein three systems in which the substitution effects are at the origin of new physical states : the high-Tc superconductor bismuth cuprate of the 2212 family, the mixed-valence manganese perovskites representative of giant magneto-resistive compounds, and the Chevrel phase materials in which a structural transition may inhibit the superconducting state.