Magnetooptical properties

In the Faraday effect, the specimen is usually a thin slab or a thin film placed between two polarisers. Fig. 4.67. The rotation angle is measured by adjusting the polarisers to maximum transmission. Domains appear with different contrasts because the magnetisation has a different orientation in each of them, as in Fig. 4.32. The rotation angle, 6, depends on magnetisation and thickness  

In the Kerr effect, the polarisation rotation can be expressed by a relation similar to Eq. (4.72), except that it is independent of specimen thickness. The Kerr effect can be observed in three geometries polar, longitudinal and transverse, shown in Fig. 4.68. The rotation angle is largest in the polar geometry, where magnetisation is perpendicular to the specimen surface. 

Magnetooptical properties of rare-earth garnets have been extensively studied because these ferrites can be prepared as single-crystal films and 

Some early experiments on GdIG (Dillon, 1959), near the compensation temperature, showed that it was not the total magnetisation, but sublattice magnetisations which determined the magnetooptical phenomena. A simple model which assumes that magnetooptical spectra can be decomposed into individual contributions from 3d cations in the several sublattices has shown reasonable agreement with experimental results. In YIG, the increase in absorption coefficient at 20 000 cm (Fig. 4.69) 

A number of ion substitutions produce a very high Faraday rotation coefficient in garnets namely, Pr and Nd (Wemple et ai, 1974), and Bi and Ce (Gomi, Satoh Abe, 1989). 

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Of practical interest are detailed studies to influence the magnetooptical properties of RE-TM materials by the substrate material and the substrate adhesion of RE-TM layers by the selected deposition technique (226). Accordingly, measurements have been performed on glass, BPA-polycarbonate, and poly(ethylene terephthalate) (as a flexible substrate). 

VALENCE BAND ORDERING AND MAGNETOOPTICAL PROPERTIES OF FREE AND BOUND EXCITONS IN ZnO... 

Schmool, D.S., Keller, N., Guyot, M., Krishnan, R., and Tessier, M. (1999) Magnetic and magnetooptic properties of orthoferrite thin films grown by pulsed-laser deposition. Journal of Applied Physics, 86, 5712-5717. 

Plastics doped by atomic clusters of ferromagnetic metals show magnetooptical properties (i.e., when subject to a strong magnetic field, they can rotate the vibration plane of a plane-polarized light), and therefore they can be used as Faraday rotators. These devices have a number of important optical applications (e.g., magnetooptic modulators, optical isolators, optical shutters, etc.). 

Blinov LM (1983) Electrooptical and magnetooptical properties of liquid crystals, Wiley, New York... 

Urner-Wille et al. (1980) have also studied ternary (Gdo.26Feo.74)i-jtSnx (0alloys prepared by the same method as the GdFeBi alloys. Such samples also have a perpendicular uniaxial anisotropy. The magnetic and the magnetooptic properties of tin alloys are similar to the ones of bismuth alloys Tcomp... 

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