Nanoindustry

The fundamental factor limiting the accuracy of surface profile measurements in scanning tunneling microscopy is the inherent, irreducible noise of the tunnel junction. This includes thermal noise, shot noise, and low-frequency flicker fluctuations. This paper presents a method for estimating the minimum measurement error of a tunneling microscope in detecting height variations of the observed surface topography, based on calculating the total spectral density of noise. The authors propose monitoring the microscope’s error magnitude using a reference standard in the picometer range.

Observation of biological specimens with nanometer-scale detail represents a highly informative and cognitively valuable task in scanning probe microscopy. This paper presents the results of observations of viruses, bacteria, neurons, and human hair.

In this work, the synthesis and characterization of nanosized chromium (III) oxide stabilized by chitosan were carried out. A study of the particle size using dynamic light scattering showed that the average hydrodynamic radius was 68 nm. A study of the optical properties revealed characteristic Cr₂O₃ bands in the absorption spectrum located in the region of 450–500 nm. Also, based on the optical density values in the absorption spectra, the band gap of the sample was found by the Tauc method, which was E_g = 3.28 eV. As a result of quantum chemical modeling, it was established that the interaction of Cr₂O₃ with chitosan is energetically favorable, regardless of the binding type (ΔE ≈ 2223 kcal/mol) and chemically stable (η < 0.124 eV). To confirm the results of quantum chemical modeling, the samples were studied by IR spectroscopy, which confirmed the optimal interaction of chromium (III) oxide with chitosan. The morphology of nanosized chromium(III) oxide was then examined, revealing that the samples consisted of porous aggregates of predominantly spherical nanoparticles ranging in size from 60 to 120 nm. Subsequently, phase analysis of the samples revealed the presence of a Cr₂O₃ phase with a rhombohedral syngony and space group R-3c.

The results of a review of information sources on the subject of laser mirrors are presented. The data on the materials of the Bregg mirrors are generalized and structured. The characteristics of the L- and H-layers are given. The choice of materials for creating a laser mirror on a multilayer oxide film is justified. The results of testing the deposition modes of nanoscale thin-film layers of silicon oxide and titanium oxide are presented. The modes are described and the results of a study of the thicknesses of silicon oxide and aluminum oxide coatings are presented. The experimental data were processed using the method of a complete factorial experiment. Regression equations describing the dependence of oxide layer thicknesses on magnetron sputtering modes are obtained. A multilayer structure consisting of alternating layers of silicon oxide and titanium oxide is shown.