Multilayers Granular materials ALEACIONES GRANULARES Approximation theory BAND STRUCTURE CALCULATIONS Band structure calculations CALCULO DE ESTUCTURA DE BANDAS ELECTRONIC TRANSPORT Electric conductivity Electronic structure GIANT MAGNETORESISTANCE GRANULAR ALLOYS Granular alloys MAGNETIC MULTILAYERS MAGNETORRESISTENCIA GIGANTE MULTICAPAS MAGNETICAS TRANSPORTE ELECTRONICO Cobalt alloys Electron transport properties Hamiltonians Magnetic multilayers Magnetismo Magnetization Magnetoresistance Percolation (solid state) Thickness measurement Transport properties Anisotropic relaxation time Antiferromagnetic resonance Antiferromagnetism