Vlasenko O. Electrophysical and magnetoresistive properties of film systems on the basis of Fe and Ge

The thesis is devoted to systematic research of electrophysical, magnetoresistive, magneto – optical galvanomagnetic properties of film systems on the basis of metal (Fe) and semiconductor (Ge) in the conditions of phase formation. In film alloys formed based on annealed to 900–1070 K three-layer films Fe(5–10 nm)/Ge(2–25 nm)/Fe(15–50 nm), depending on the ratio of the concentrations of atoms of individual components, magnetic films are formed iron germanides Fe2Ge, FeGe and FeGe2 with average crystallite sizes of 15–30 nm. Comparison of resistivity of two-layer Ge/Fe/S (S-substrate) film systems with calculated ones based on the model, which preserves the individuality of individual layers, indicates that the difference between these values can be explained by the effect of Vanier-Mott excitons based on 4 % conduction electrons. It is established that in systems based on Fe and Ge films, the dependence of the angle Θ on the induction of the magnetic field in the form of a "stepped hysteresis loop" is observed, which indicates the realization of two magnetic states and the speed of sensitive elements of functional devices in a magnetic field. It has been experimentally established that the value of the Hall constant for two-layer films based on Fe and Ge (6–11)·10–9 m3/C with increasing magnetic field induction from 0 mT to 100 mT. When increasing the heat treatment interval of film samples to 570 K, the value of the Hall constant decreases from 11·10–9 m3/C to 6·10–9 m3/C. The properties of thin films of carbon and carbon nitride as protective coatings for film sensitive elements have been studied.