Vol 87, No 10 (2023)

The morphology and composition of aerosol particles in the surface Moscow atmosphere have been studied by scanning electron microscopy and X-ray spectral microanalysis. The results are interpreted considering seasonal, synoptic, and meteorological conditions. The main morphological types of particles of natural and anthropogenic origin are revealed.

The results of fractal analysis of images of the surface of a permanent magnet KS37, obtained by the method of the polar Kerr effect using an indicator bismuth-containing ferrite-garnet film after magnetization reversal by a pulsed field of 0.1–1.5 T, are presented. The obtained dependences of the residual magnetization on the magnitude of the external pulsed field are compared with the fractal dimension of the magneto-optical images of the magnet surface after exposure to the pulsed field. It is shown that the maximum value of the fractal dimension corresponds to the demagnetized state of the magnet.

The piezoelectric properties of vertically aligned carbon nanotubes (CNTs) are characterized using the piezoresponse force microscopy method. Dependence of piezoelectric properties on the nitrogen concentration is established. It is shown that CNTs have predominantly longitudinal polarization due to the direction of the dipole moment in the bamboo-like “bridges”. It has been established that a decrease in the growth temperature from 690 to 645°С leads to an increase in the piezoelectric strain coefficient of CNTs from 4.5 to 21.2 pm ⋅ V^–1. The obtained results can be used in the development of energy-efficient nanopiezotronic devices.

Carbon nanoparticles are a common type of nanoparticles, the identification of which in biological samples is associated with great difficulties. It is demonstrated that the use of standard transmission electron microscopy in combination with the electron diffraction method is a reliable and relevant tool for the carbon nanoparticles identification in biological samples.

The impact of the irradiation with focused helium ion beam and electron beam on the cathodoluminescence (CL) of hexagonal boron nitride was investigated. It was shown that the irradiation with helium ions resulted in a decrease of the intensity of CL in the region 200–700 nm. Subsequent irradiation with electrons results in an increase of the intensity of 2 eV CL band comparing with its intensity in pristine material.

The structure and properties of TiN_x electrodes obtained by plasma-enhanced atomic layer deposition in the 20 nm TiN_x/10 nm La: HfO₂(Hf_0.5Zr_0.5O)/20 nm TiN_x/1 μm SiO₂ system have been studied by electron microscopy and electron energy loss spectroscopy. It is shown that the electrode material has a TiN_xO_y composition, the band gap width varies within 1.7–2.5 eV, the resistivity is 208 μOm cm and the value of the temperature coefficient of resistance (20–100°C) is equal to –31.4 ⋅ 10^–6 1/K.

The effect of annealing time on the structural and optical properties of ZnO films, which are formed from Zn films obtained by magnetron sputtering followed by oxidation in air, is described. Thermal oxidation in air was carried out for 7 and 24 hours, respectively, in a programmable muffle furnace at T = 750°C. A change in the structure of the film surface depending on the annealing time of the Zn film and the substrate material was found, which manifests itself in the optical properties of the films.

It is shown that the features of light propagation in plant leaves depend on the long-range ordering in chloroplasts and spectral characteristics of pigments. It has been established that, with regard of the dispersion of the chlorophyll absorption spectrum, the photonic density of states increases and the spectral peak shifts to the effective photosynthesis wavelength range, which enhances the probability of the photosynthesis processes.

The problem of a model choice for description of broad absorption–dispersion relaxation bands in the dielectric spectroscopy is discussed. An example of the spectra processing difficulty negotiation by replacing the Debye relaxation with the overdamped Lorentzian is given.

Intermittent behavior near the boundary of phase synchronization in systems with a complex topology of attractor is studied. Using the calculation of statistical characteristics of the laminar phase lengths it is shown that in the case of a relatively small detuning of the control parameters of interacting systems near the phase synchronization boundary the eyelet intermittency takes place.

The general nonreciprocal properties of surface and backward spin waves in a tangentially magnetized ferrite plate are investigated. It is established the rule that determines interconnection between the spin wave localization over the ferrite plate thickness and the directions of group and phase velocities of the wave.

The problem of determining the low-frequency electromagnetic radiation spectrum of lightning activity zones based on the analysis of data obtained from a space-based high-speed camera is investigated. A novel method is proposed for obtaining the electromagnetic spectrum of lightning, based on the hypothesis of the correlation of the time dependences of the radiation intensity of the same lightning discharge, measured in the optical and electromagnetic ranges. The necessity of conducting studies of the influence of local lightning on the processes associated with the Schumann resonance is substantiated.

Magnetic force microscopy was used to investigate the effect of magnetic pulse treatment on the local magnetic properties of the surface of ribbon amorphous Fe(Ni,Cu)(SiB) alloys obtained by ultrafast cooling by melt spraying on a rotating copper drum.