The magnetic and magneto-optical properties of the typical representatives of three rare-earth iron garnets (RIG) groups: with heavy rare-earth elements Yb, Er, Dy, Tb; with elements from the middle of lanthanide series Gd, Sm, and with light rare-earth element Nd are presented. In contradistinction to other work on the Faraday rotation, which were done only at 1152 nm (8696 cm −1 ), here we present FR spectra obtained in the energy region 5500-20000 cm −1 with high optical resolution. The investigations have been done at temperatures of 5, 82, 130, 295 K using magnetic field up to 25 kOe applied parallel to the [111] crystallographic axis of the crystals. It has been shown that the contribution proportional to the magnetic field and independent of temperature to the mixing of the ground state multiplets exceeds the paramagnetic contribution in YbIG, ErIG, GdIG, SmIG. In Tb and Dy iron garnets contributions from the two mechanisms have opposite signs, and the paramagnetic mechanism gives the greatest contribution to the Faraday rotation. Nevertheless, the contribution of the diamagnetic mechanism, caused by the influence of the exchange field in the iron sublattices on rare-earth ions, is significant, and it is necessary to take it into account. Anomalously large magneto-optical activity is observed in NdYIG. This is the result of contributions of the same sign and approximately equal in magnitude from the paramagnetic and diamagnetic mechanisms.

Rare earth iron garnets with narrow ferromagnetic resonance linewidths, very low hysteresis losses, and excellent dielectric properties have been widely applied in microwave devices in a wide range of frequencies (1100 GHz), magnetooptical transducers and typically employed as magnetic recording media [1-1. The rare earth iron garnets which can be described by chemical unit formulaRE3Fe5O12belong to cubic system with space groupIa3̄d, whose cell contains eightRE3Fe5O12molecules and crystal lattice contains three crystallographic sites, dodecahedral site 24c{RE3+}, octahedral site 16a[Fe3+] and tetrahedral site 24d(Fe3+). The garnet in fact does not allow distortion to lower symmetry owing to its non-efficiently packed structure, which makes iron garnet structure become unstable with increasing rare earth ionic radius.

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In this paper we present an experimental study of migration of atoms and molecules of the substrate material in the thickness of the film in the direction of the surface by means of laser desorption mass spectrometry. The method is based on the time-of-flight principle of particle detection, desorbed from the sample surface by a laser pulse (LP) of nanosecond duration [. The main advantage of TOF mass spectrometer is that the registration of product desorption is carried out at the site of direct flight from the sample to the ion source, i. e. in the mass spectrum does not participate particle, reflected from the walls and other elements. In addition, the method allows to measure the time delay of the particles emission, relative to the exciting laser irradiation [.

After the discovery of antiferromagnetic interaction [, giant magnetoresistance [ and oscillating magnetic interaction [, the exchange coupling between magnetic layers across the conductive nonmagnetic spacer layer in multilayer structures have been attracted much attention [4-.