Giant magnetorefractive effect in La0.7Ca0.3MnO3 films

Giant magnetotransmission and magnetoreflection in ferromagnetic materials

“…3a); in the films of the same composition the effect is higher due to multiple reflections of light from the film-substrate boundary [42]. Sample surface roughness and impurity distribution across the skin-depth or along the surface of crystal may also affect the magnetoreflection.…”

“…This peculiarity is the most pronounced near the first phonon band of reflection spectra of manganites. The value of this resonance-like contribution depends on the manganite inhomogeneity and differs for films of different thicknesses [27,41,42].…”

“…Therefore the temperature and field dependences of magnetotransmission are quite different at different wavelengths. Moreover, the magnitude of magnetotransmission depends on the film thickness, the mechanical stresses, and the interface phenomena [27,[41][42][43][44]. Notice that because of quasi-local character of the magnetotransmission (different optical responses from conducting and non-conducting areas) the Δt/t measurements are a good tool for studying the magnetic and charge inhomogeneity in CMR materials [45,46].…”

Magnetorefractive effect in manganites with a colossal magnetoresistance in the visible spectral region

“…The choice of the different compositions of the films under investigation has been motivated by the study of the influence exerted on the magnetorefractive effect by the univalent and divalent substitutions for lanthanum. For these compositions, we have well investigated the magnetic, magnetotrans port, and optical properties, as well as the specific fea tures of the magnetorefractive effect in the IR spectral region [10,12]. This has made it possible to perform a comparative analysis of the mechanisms responsible for magnetoreflection and magnetotransmission in the visible and IR regions of the spectrum of these manga nites.…”

“…Recently, Hrabovsk et al [8] and Caicedo et al [9] showed that, in the visible spectral region, the even effect of magnetoreflection in the vicinity of the Curie temperature (T C ) in the mangan ites La 0.7 Ca 0.3 MnO 3 and (Pr 0.4 La 0.6 ) 0.7 Ca 0.3 NbO 3 can reach 2% (for an oblique incidence of light at an angle of 45° in a magnetic field of 7 kOe), which is one or two orders of magnitude greater than the conventional odd magneto optical effects observed at the same tem peratures and wavelengths, although it is considerably smaller than the magnetorefractive effect revealed in the IR region of the spectrum. The observed effect was investigated only for reflection, in the case where the reflection from the substrate can have a significant effect on the magnitude and spectral dependence of the magnetorefractive effect of thin films [10], and was y ' attributed to the influence of a strong magnetic field on polarons [9].…”