In the wavelength range of 1.5—20 μm optical reflection and the evenmagnetization magnetorefractive effect (MRE) were studied in the nanocomposites: ferromagnet (Co, Fe, CoFe, CoFeZr)-dielectric matrix (А1$_2$О$_3$, SiC$_2$, ТiO$_2$, MgF) that possess tunnel magnetoresistance of compositions near the percolation threshold. Dispersion of these effects depending on the polarization, angle of light incidence and applied magnetic field were investigated. It was shown that extreme values of MRE corresponded to minimal optical reflection and reached levels dozens of times greater than the traditional Kerr effects. Experimental data indicate that this effect is the result of spin-dependent tunneling of conduction electrons at optical frequencies.
$^1$Department of Physics, Moscow State University, Moscow, 119991, Russia
$^2$Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences
Science News of the Faculty of Physics, Lomonosov Moscow State University
This new information publication, which is intended to convey to the staff, students and graduate students, faculty colleagues and partners of the main achievements of scientists and scientific information on the events in the life of university physicists.