Infrared magneto-optical composite materials based on manganite powders

Abstract

First results on the study of the magneto-optical properties of powder composites based on doped manganites are presented. A giant change of the intensity of unpolarized infrared light transmitted through the composites under the external magnetic field applied (magnetotransmission effect) has been revealed. The optical properties of manganite composites and the magnitude of magnetotransmission effect were similar to those for the epitaxial films. The powder composites based on doped manganites seem to be prospective for the creation of any alternative infrared magnetooptical elements driven by the magnetic field.

Giant magnetotransmission and magnetoreflection in ferromagnetic materials

“…In 1999 positive magnetoreflection effect was also found in CMR manganites [30]. Both the effects were studied in single crystals, polycrystals, thin films, heterostructures, multilayers, and optical composites based on manganites [31][32][33][34][35][36]. It was shown theoretically [36] that in manganites the ΔR/R and Δt/ t effects are optical responses on colossal magnetoresistance in the infrared spectral region.…”

“…Being quite large, in some cases up to 50%, which is giant for magneto-optics, nongyrotropic, independent of orientation of magnetic field and light polarization at small angles of light incidence, the magnetoreflection and magnetotransmission can be successfully used in magnetophotonic. In particular, the giant magnetotransmission and magnetoreflection of light in the CMR manganites allowed recommending these ferromagnetic materials for practical applications, for example, creating magnetic "lens", infrared radiation modulators, high-frequency optical isolators and attenuators, temperature indicators and so on [33,35,39,52,[54][55][56][57][58]. Since the manganites exhibit strong magnetooptical response, it is possible to utilize both gyrotropic and nongyrotropic effects in one device.…”