Determining the tunnel spin-polarization density of states near the Fermi level using IR magnetoreflectance spectroscopy

► The magnetorefractive effect and tunnelling magnetoresistance in ferromagnetic metal-insulator multilayer films were measured. ► The spin-polarization density of states around the Fermi level was extracted from the magnetoreflection spectra. ► A high degree of correlation between the TMR and MRE effects was found. ► Such behaviours of multilayers materials are important for creating new spintronic devices and magnetophotonic crystals.