The transport properties of the Tm x Mn 1-x S (x 0.15) solid solutions in the temperature range of 200-600 K have been investigated. The temperatures of lattice polaron pinning accompanied by the lattice strain, condensation of the infrared modes, and thermionic emission have been determined. The change of the carrier sign with temperature has been found from the Hall coefficient data and dragging of electrons by phonons, from the thermopower data. The dependence of the magnetoresistance on the concentration, current, and voltage has been established from the I-V characteristics measured without field and in an applied magnetic field of H ¼ 8 kOe in the temperature range of 300-500 K. The functional temperature dependence of the carrier relaxation time has been determined using the impedance data. The concentration region with the magnetoimpedance sign varying with frequency and temperature has been found. The increase in the relaxation time of the induced electric polarization with increasing concentration of thulium ions has been observed. The experimental data have been interpreted in the framework of the Debye and Maxwell-Wagner models, as well as the theoretical model for the Rashba spin-orbit interaction.

Mode hybridization is a unique way to manipulate the mode inside a fixed cavity or at interface. For example, Tamm plasmon-polariton at solid interface can be spectrally shifted without tuning the interface. Experimental implementation of tunable hybrid Tamm-microcavity modes is reported. The hybrid modes are excited in a one-dimensional photonic crystal bounded with a gold layer by attaching a nematic liquid crystal microcavity. Coupling between Tamm plasmon-polariton and microcavity modes leads to repulsion of their dispersion curves controlled by the refractive index of a liquid crystal and the polarization of incident light. Effective tuning of hybrid modes through heating or applying an external electric field to the liquid crystal layer is demonstrated. The experimentally measured strength coupling value between Tamm and microcavity modes was 20.7 meV.

This article presents the results of the study of metal/insulator/semiconductor (MIS) hybrid structures transport properties in alternating current (ac) mode. We prepared a series of samples with different layers of metal, insulator and semiconductor. Ferromagnetic Fe and non-magnetic Cu and Mn were chosen as metals, the insulators were SiO 2 and Al 2 O 3 , Si substrates of n-and p-type were used as semiconductors. Temperature dependence of real part of the impedance showed peculiar peaks below 40К for different combinations of metals, insulators and semiconductors. For all samples the effect of magnetic field on the transport properties was studied. At low temperatures, the magnetic field shifts peaks toward higher temperatures. Metal magnetic state doesn't significantly affect this phenomenon. Changing the type of the insulator and its thickness also didn't cause any significant effect. The effect was observed for samples with different composition. However, the type of conductivity of the substrate, as well as the type of metal, determines the value of magnetoimpedance (MI). The main role in the magnetoimpedance effect is played by recharging of energy states localized at insulator/semiconductor interface. This mechanism allows obtaining MI effect even in "nonmagnetic" MIS structures; MI can be either positive or negative, depending on temperature and frequency. We suggest that the observed ac magnetotransport phenomena could be used for creating magnetic field sensors, working on new principles.

The photoinduced diode effect has been found in BiMn X Fe 1−X O 3 (0<Х<0.15) films in the near-infrared and violet spectral ranges in a wide temperature interval. The dependences of the diode effect on temperature, wavelength, and illumination power have been established. The mechanism of the ferroelectric diode has been determined using its I-V characteristics at different illumination powers, optical spectra, far-infrared absorption spectra, and electric polarization hysteresis. The interplay between the photodiode effect and conductivity mechanism has been elucidated. The model of strong Coulomb potential fluctuations and quantum well asymmetry caused by the electric polarization in the film and difference between the times of carrier thermalization and recombination of electrons and holes is proposed.

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