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The possibility of using implantation of 20-keV He+ ions for modification of the domain structure and magnetic properties of CoPt films (formed by the electron-beam evaporation method) with different cobalt contents (Co0.45Pt0.55 and Co0.35Pt0.65) has been investigated. A decrease in the coercive field (narrowing of the hysteresis loop in the magnetic-field dependences of the Faraday angle and magnetization) with an increase in the He+ ion fluence from 2 × 1014 to 4 × 1014 cm–2 has been found for the irradiated CoPt samples of both compositions. The residual magnetization of the Co0.35Pt0.65 films coincides with the saturation magnetization, and a decrease in the residual magnetization is observed for Co0.45Pt0.55. It is shown by magnetic force microscopy that the largest number of round isolated domains (skyrmions) for the Co0.45Pt0.55 alloy are formed when the ion fluence increases to 3 × 1014 cm–2, while 360-degree domain walls (1D skyrmions) are observed along with round isolated domains for the Co0.35Pt0.65 films irradiated with a He+ fluence of 4 × 1014 cm–2. An analysis of CoPt films by Mandelstam–Brillouin spectroscopy revealed an increase in the shift between the Stokes and anti-Stokes components of the spectrum and a significant enhancement of the Dzyaloshinski–Moriya interaction in the irradiated samples. Model calculations performed using the SRIM program showed that the ion irradiation facilitates asymmetric mixing of Co and Pt atoms in CoPt films, which may underlie the mechanism of the observed effects of ion irradiation on their magnetic properties and domain structure.

The effect of ion irradiation on magnetic properties of films of the ferromagnetic CoPt alloy fabricated by electron-beam evaporation has been studied. It is found that the coercive force decreases and the lateral component of the easy-magnetization axis increases as the He+ ion fluence increases from 1 × 1013 to 1 × 1016 cm–2. It is shown by magnetic-force microscopy and the Mandelstam–Brillouin spectroscopy that the formation of isolated circle domains which are magnetic skirmions in the CoPt layer is activated at certain ion-irradiation fluence (3 × 1014 cm–2).

The influence of He+ ion irradiation on magnetotransport properties of epitaxial layers of a diluted magnetic semiconductor (DMS) (In,Fe)Sb, a two-phase (In,Fe)Sb composite and a nominally undoped InSb semiconductor has been investigated. In all layers, a conductivity type conversion from the initial n-type to the p-type has been found. The ion fluence at which the conversion occurs depends on the Fe concentration in the InSb matrix. Magnetotransport properties of the two-phase (In,Fe)Sb layer are strongly affected by ferromagnetic Fe inclusions. An influence of the number of electrically active radiation defects on the magnetic properties of the single-phase In0.75Fe0.25Sb DMS has been found. At the same time, the results show that the magnetic properties of the In0.75Fe0.25Sb DMS are quite resistant to significant changes of the charge carrier concentration and the Fermi level position. The results confirm a weak interrelation between the ferromagnetism and the charge carrier concentration in (In,Fe)Sb that is fundamentally different from Mn doped III-V DMS.

We have studied the resistive switching in memristive structures based on 40-nm-thick yttria-stabilized zirconia (YSZ) films exposed to 6-keV Si+ ion irradiation to a total dose of 5.4 × 1015 cm–2. It is established that the ion irradiation leads to increased stability of the parameters of resistive switching in YSZ based memristive structures. This effect is related to the fact that the diameter of conducting filaments in irradiated structures is limited by lateral dimensions of the region of atomic displacement cascades (i.e., the region occupied by point defects produced by bombarding ions). The oxidation of ion-modified filaments during resistive switching proceeds more effectively and leads to increasing resistance in the high-resistance state of memristive structures.

The paper presents a method for manufacturing mechanically strong sputtering composite targets containing the phase of the Co2FeSi or Co2MnSi Heusler alloy of the stoichiometric composition, which can be used for fabrication of spin electronic devices by high-frequency magnetron deposition and pulsed laser deposition of thin films.

The photoluminescence spectra of erbium centers in SiO2 films with ion-synthesized silicon nanoclusters under nonresonant excitation were investigated. Erbium was introduced into thermal SiO2 films by ion implantation. The dependences of photoluminescence intensity on the dose, the order of ion implantation of Si and Er, the annealing temperature, and additional Ar+ and P+ ion irradiation regimes, i.e., factors determining the influence of radiation damage and doping on sensitization of erbium luminescence by silicon nanoclusters, were determined. It was found that the sensitization effect and its amplification due to doping with phosphorus are most pronounced under the conditions where nanoclusters are amorphous. The quenching of photoluminescence due to radiation damage in this case manifests itself to a lesser extent than for crystalline nanoclusters. The role of various factors in the observed regularities was discussed in the framework of the existing concepts of the mechanisms of light emission and energy exchange in the system of silicon nanoclusters and erbium centers.

We have studied the photoluminescence (PL) of GeO2 and 90 mol % SiO2-10 mol % GeO2 films synthesized by method of RF magnetron sputtering and then irradiated with silicon ions and annealed. The PL of silicon-implanted GeO2 films, related to the presence of Si nanocrystals (nc-Si), was observed for the first time. It is established that the transformation of the defect centers responsible for the PL in the spectral range 350–600 nm, as well as the formation of nc-Si emitting in the region of 700–800 nm, significantly depend on the matrix type. In particular, the PL intensity at 700–800 nm in 90 mol % SiO2-10 mol % GeO2 films is weak. The role of the isovalent substitution of Si and Ge atoms in the transformation of defect centers and the formation of nc-Si is discussed.