Magneto-Optic Spectra of EuS-Gd and EuS-Tb Films

Doping EuS films with Tb or Gd increases the Curle point because of strong exchange through the free carriers and increases the coerclvity because of strong crystal fields associated with vacant sulfur sites. The two main features of the reflectivity spectra of the doped samples are a strong free carrier contribution below 1.5 eV and aregion of low reflectance between 1.5 and 4 eV. The Kerr peak In EuS at 2.4 eV greatly enhanced In some of the doped compositions probably as a consequence of low value. of the optical functions n(ω) and k(ω) In this low reflectance region. © 1992 IEEE