The Study of the Applicability of Electron Irradiation for FeNi Microtubes Modification

Abstract

The paper presents the results of a study of irradiation of high-energy electrons by an array of FeNi nanostructures with doses from 50 to 500 kGy. Polycrystalline nanotubes based on FeNi, the phase composition of which is a mixture of two face-centered phases, FeNi3 and FeNi, were chosen as initial samples. During the study, the dependences of the phase transformations, as well as changes in the structural parameters as a result of electronic annealing of defects, were established. Using the method of X-ray diffraction, three stages of phase transformations were established: FeNi3 ≅ FeNi → FeNi3 ≪ FeNi → FeNi. After increasing the radiation dose above 400 kGy, no further phase changes were followed, indicating the saturation of defect annealing and completion of the lattice formation process. It was found that an increase in the degree of crystallinity and density of the microstructures as a result of irradiation indicates electronic annealing of defects and a change in the phase composition. It was established that the initial microtubes, in which two phases are present, leads to the appearance of differently oriented crystallites of different sizes in the structure, which contributes to a large number of grain boundaries and also a decrease in density, and are subject to the greatest degradation of structural properties. For modified samples, the degradation rate decreases by 5 times. In the course of the study, the prospects of the use of electron irradiation with doses above 250 kGy for directed modification of FeNi microtubes and changes in structural features were established.

The study of the applicability of invar nanostructures for the reduction of p-nitrophenyl compounds

“…The difference in the applied potentials for deposition was 1.75 V. The iron and nickel salts FeSO 4 × 7H 2 O, NiSO 4 × 7H 2 O in a given molar ratio were used as the electrolyte solution. The addition of boric (H3BO3) and ascorbic (C 6 H 8 O 6 ) acids was used to achieve the required solution pH of 3, and also as buffer compounds to accelerate the crystallization of crystallites on the walls of tracks in polymer matrices [14,15].…”

“…The structural properties and phase composition of the synthesized microstructures were modified using an ELV -4 linear accelerator (Kurchatov, Kazakhstan) by irradiating an irradiation dose of 50-500 kGy with a step of 50 kGy with an energy of 5 MeV [15]. The studied microstructures were irradiated in air.…”

“…One of the most common catalytic reactions for studying the processes of reduction of nitro groups in the presence of catalysts is the reaction of reduction of toxic p-nitrophenyl compounds to p-aminophenyl compounds, which are safe [14,15]. The aim of this work is to study the effect of electron-beam modification of iron-nickel nanostructures on the catalytic activity in the reduction reaction.…”

Investigation of the Structural Changes and Catalytic Properties of FeNi Nanostructures as a Result of Exposure to Gamma Radiation

“…At the same time, when irradiated with electronic and gamma radiation, the probability of an increase in the geometric dimensions of nanostructures is extremely small, which indicates the great promise of these types of radiation for directional modification and reduction of the disequilibrium of structural parameters in nanomaterials [16][17][18][19][20]. The absence of oxidation processes as a result of phase transformations upon irradiation with electrons or gamma rays opens up wide possibilities for using these types of radiation for the directed modification of iron-nickel or iron-containing nanostructures, for which oxidation processes are accompanied by phase transformations and changes in properties [21][22][23][24][25]. Permalloy compounds, which have high magnetic permeability, low coercivity and magnetostriction, which classifies them as soft magnetic materials, are some of the most promising materials among iron-containing nanostructures [26][27][28][29][30].…”