Features of absorption of thin films La$_{0.69}$Ba$_{0.31}$MnO$_{3-\delta}$ obtained using the method of pulsed laser deposition

The electrical, optical, and magneto-optical properties of La$_{0.69}$Ba$_{0.31}$MnO$_{3-\delta}$ thin films with a Curie temperature near room temperature are studied. It is shown that in the region of the phase transition there is a sharp change in the behavior of the temperature dependences of the electrical resistance and optical transparency of the films, which is associated with the insulator-metal transition. In a narrow temperature region near the transition, a change in the external magnetic field leads to the appearance of negative magnetoresistance and magnetotransmission of unpolarized light in the spectral range from 1 to 12 $\mu$m. It is shown that the effect of magnetic transmission (magnetoabsorption) in films is mainly due to the contribution of free charge carriers. The magnetic transmission spectra are sensitive to the magnetic and electronic inhomogeneities of the films.