  The features of electronic structure of La0.7Sr0.3MnO3, Pr0.8Sr0.2MnO3, and
Pr0.6Sr0.4MnO3 polycrystalline films of different thickness have been
investigated using magnetic circular dichroism (MCD) in the range of 1.1-4.2
eV. The temperature behavior of the samples electrical resistance were also has
been studied. It was found that films with high Sr content (0.3 and 0.4) act as
high-temperature semiconductors, while the maximum in the temperature
dependences of these films resistivity indicates the transition of the samples
to the metallic state at some temperature TM-S, which is different for
different sample thickness. The films with the lower Sr content (0.2) act as
insulators in the used temperature range. The MCD spectra have been decomposed
to the Gaussian-shaped lines, and the temperature dependence of intensity of
each line has been analyzed in comparison with temperature dependence of the
films magnetization and with their electric conductivity type. Different
temperature behavior of the intensity of four specified Gaussian-lines was
revealed for semiconductor films. In the case of insulating Pr0.8Sr0.2MnO3
samples, the intensity of three specified Gaussian lines changes with the
temperature in the same way as the magnetization changed. It was established
that the lanthanide (La, Pr) type does not affect the MCD spectra shape for the
films with the same electrical conductivity type. Besides, the correlation
between the MCD data of the films and their conductivity type was revealed. Due
to the detailed analysis of the specified Gaussian lines with taking into
account the well-known in the literature absorption bands, lying outside the
studied spectral region, the MCD bands for the studied manganite films have
been identified with electronic transitions of a different nature.
