Observation of subkelvin superconductivity in Cd₃As₂ thin films

We report an experimental observation of superconductivity in Cd3As2 thin films without application of external pressure. The films under study were synthesized by magnetron sputtering. Surface studies suggest that the observed transport characteristics are related to the polycrystalline continuous part of the investigated films with a homogeneous distribution of elements and the Cd-to-As ratio close to stoichiometric Cd3As

The effect of vacuum annealing on the structure and properties of the electrically conductive a-CN coating

Electrically conductive amorphous carbon nitride (a-CN) coatings were deposited onto various substrates by pulsed vacuum-arc sputtering of a graphite cathode with simultaneous irradiation of the substrate with nitrogen ions. Deposition temperature was less than 60 ◦C. We investigated the effect of vacuum annealing at a temperature of 600◦С on the elemental composition, structure, electrical and optical properties of the obtained films. It was found that the elemental composition of the coating practically does not change over the thickness of the coating after annealing, while the remaining characteristics change significantl

Berry Phase in single crystals of the dilute magnetic semiconductor (Cd₀.₇Zn₀.₂₈Mn₀.₀₂)₃As₂

Investigations of transverse magnetoresistance have been performed on single crystals of diluted magnetic semiconductor (Cd₀.₇Zn₀.₂₈Mn₀.₀₂)₃As₂ (CZMA). Based on analysis of the Shubnikov-de Haas (SdH) oscillations, observed in the temperature range T = 4.2 ÷ 30 K and at transverse magnetic field B = 0 ÷ 11 T, the phase shift, β, indicating the presence of the Berry phase was determine

Structural properties and variable-range hopping conductivity of Cu₂SnS₃

In the present work, we investigated the elemental composition, structural and electrical properties of Cu₂SnS₃ (CTS) ternary semiconductor synthesized by the pyrolytic decomposition of the precursors in vacuu

Resistivity superconducting transition in single-crystalline Cd0.95Ni0.05Sb system consisting of non-superconducting CdSb and NiSb phases

Resistivity superconducting transition has been for the first time found in single crystal of twocomponent 0.95(CdSb)-0.05(NiSb) system. End members of the system are not superconductors under normal conditions. Insulating behavior in temperature dependence of the electrical resistivity, which is due to hopping conductivity, precedes the transition. The resistivity superconducting transition is rather broad, since at cooling down the electrical resistivity starts to fall at 10.5 K, whereas zero resistivity is reached only at ~2.3

Two-dimensional surface topological nanolayers and dirac fermions in single crystals of the diluted magnetic semiconductor (Cd1–x–yZnxMny)3As2 (x + y = 0.3)

Features in the transverse magnetoresistance of single-crystalline diluted magnetic semiconductors of a (Cd1–x–yZnxMny)3As2 system with x + y = 0.3 have been found and analyzed in detail. Two groups of samples have been examine

Calculation of the band structure and density of localized states of materials of the quasi-binary system Zn₃As₂- Mn₃As₂

Investigations of materials of the quasi-binary system Zn₃As₂- Mn₃As₂ have been performed. We present band structure calculations of crystal structures of Zn₃As₂, Mn₃As₂ and ZnMn₂As₂ within the framework of the density functional theory (DFT) and DFT + U method. The calculations based on first-principles were made using plane waves normalized on pseudopotential with the Quantum Espresso software package. Was obtained, that fundamental gap for Mn₃As₂ and Zn₃As₂ is equal to the optical band gap, while the band gaps for ZnMn₂As₂ was close

Synthesis and magnetic properties of solid solutions of a diluted magnetic semiconductor (Zn₁-xFex)₃As₂

The magnetic properties of the new semimagnetic semiconductor (Zn₁-xFex)₃As₂ with x < 0.04 have been investigated over a wide temperature range. Single crystals of ZFA were grown using the modified Bridgeman technique. The results of X-ray analyses and the magnetometry data show that the border of solid solutions in this system lay near x = 0.015. Further increasing of x leads to the growing of the second phase, which was identified as Fe₂As. A notable feature of our magnetometry results is the spin-glass-type freezing of magnetic moments in the temperature range of 10 - 50

Recycling and disposal of gypsum-containing waste generated in the production of citric acid

The cycle of citric acid production with the formation of gypsum-containing waste was considered and options for processing and utilization of citrogypsum were proposed. The methods obtained include: the use of citrogypsum in the production of building materials, the extraction of rare earth metals, as well as the creation of a high-quality organic-mineral fertilizer, during the creation of which it is possible to reduce the negative effect not only from the accumulation of citrogypsum, but also from manure stored in the filtration field