Origin of magneto-optic enhancement in CoPt alloys and Co/Pt multilayers

The magneto-optical (MO) Kerr effect in CosPt1-s alloys follows from the permittivity tensor component epsilon(xy) times the function v(N) of the refractive index, N. Re(epsilon(xy)) displays a maximum at the photon energy (h) over bar omega approximate to 1 eV, vertical bar v[N((h) over bar omega)]vertical bar increases 30 x from 1 to 6 eV. Re(epsilon(xy)) creates a low (h) over bar omega peak in polar Kerr rotation (PKR). The PKR peak above 3.6 eV results from v[N((h) over bar omega)] that modulates Re(epsilon(xy)). The Re(epsilon(xy)) maximum reduces with s while vertical bar v[N((h) over bar omega)]vertical bar above 4 eV becomes steeper. PKR peak at (h) over bar omega > 3.6 eV originate mostly from v(N). The mechanism affects MO effects in other ferromagnetic metals and alloys. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4726121]