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Electrical and optical properties of thin iron layers grown at room temperature on the epitaxial silicide Si(111)-(2 × 2)-Fe phase and on an Si(111)7 × 7 surface were investigated using in situ Hall effect registration, atomic force microscopy, and optical spectroscopy. It was established that Si(111)-(2 × 2)-Fe phase has semiconducting properties with a 0.99 eV effective band gap and acts as a diffusion barrier for the deposited iron atoms, preventing intermixing with the substrate at room temperature. Peculiarities in the optical spectra of a sample with a 2 nm iron film grown on the Si(111)-(2 × 2)-Fe phase typical for both metal and semiconducting natures prove a conservation of the phase under the iron layer. The process of iron growth on the Si(111)-(2 × 2)-Fe phase is accompanied by the development of high stress in the subsurface area resulting in band dispersion changes. Apparently the tension reaches a maximum at an iron layer thickness of 1.35 nm, and a high effective hole mobility equal to 820  cm(2) V(-1) s(-1) was registered.

Polycrystalline and oriented films of barium disilicide (BaSi2) with a thickness of up to 100 nm were formed on silicon (111) substrates by high-temperature (800 ° C) solid-phase (single-stage and two-stage) annealing. The single phase of barium disilicide films and their semiconductor nature have been proven to be below 1.25 eV according to X-ray and optical spectroscopic methods. Two preferential orientations of the BaSi2 crystallites were detected and their orientation was determined in the films formed by two-stage annealing. According to the calculations of the parameters of the crystal structure of BaSi2 films, a compression of the unit cell volume from 2.7% to 5.13% was found, depending on the cooling time to room temperature. The stability of the films to laser radiation was studied by registering the Raman spectra with a variable power of laser radiation. The maximum power density of the laser beam (3⋅109 W/m2), which does not lead to the beginning of the destruction of these films, was determined.

BaSi2 thin films were formed on Si (111) substrate by solid-phase epitaxy (SPE) (UHV deposition) using the template technology followed by vacuum annealing at temperatures of 600 °C and 750 °C. After the deposition and annealing barium silicide films were characterized by Auger electron spectroscopy, grazing incidence x-ray diffraction (GIXRD) and atomic-force microscopy (AFM). It was established that the films annealed at T = 600 °C are polycrystalline with the structure of the orthorhombic BaSi2, with grain sizes of 100-200 nm. Higher anneal temperature (T=750 °C) leads to increase of diffraction peak intensity of BaSi2 phase with grain coagulation into 300-400 nm islands. It was confirmed that nanocrystalline BaSi2 films are characterized by a direct fundamental interband transition at 1.3 eV, the second interband transition with an energy of 2.0 eV, own phonon structure with wave number peaks at 112, 119, 146 and 208 cm-1 and a high density of defect states within the band gap, which provide a noticeable subband absorption at energies of 0.8 – 1.1 eV.