Technobius Physics

Exploring the phase composition and crystal structure of potassium-doped copper sulfide

Saira Sakhabayeva, Azat Nurkasimov, Murat Kasymzhanov, Zhanat Baizhanov — Tue, 12 Nov 2024 00:00:00 +0500

This study investigates the phase composition, crystal structure, and phase transitions of potassium-substituted copper sulfide (K_xCu_1.97-xS), focusing on the effects of potassium doping on the material’s properties. Using X-ray diffraction analysis, we identified the structural characteristics of potassium-doped variants, confirming their retention of the monoclinic chalcocite structure (P21/c) with slight modifications in lattice parameters. The incorporation of potassium ions resulted in observable changes in the unit cell dimensions, suggesting enhanced ionic interactions and potential impacts on electronic conductivity. The thermoelectric coefficient, electro-conductivity, and thermoelectric power were also examined, revealing that potassium doping could stabilize certain phases under varying temperature conditions. This work provides valuable insights into the structure-property relationships in copper sulfides, highlighting the potential for tailored materials in thermoelectric applications and other advanced technologies. Future studies will explore the implications of these findings for optimizing the performance of potassium-doped copper sulfides in practical applications.

Effect of ethanol on the structure and aggregation properties of C₆₀ fullerenes

Hakan Ozbay — Mon, 23 Dec 2024 00:00:00 +0500

This study investigated the effect of ethanol on the structure and aggregation properties of C₆₀ fullerenes using an atomic force microscope. The fullerenes were dissolved in ethanol with different concentrations (0%, 10%, 25%, 50%, 100%) and deposited on silicon substrate for further analysis. The results showed that the size of molecular aggregates of fullerenes increased significantly with increasing ethanol concentration, starting from 15-20 nm in the absence of ethanol and reaching 80-100 nm at 100% ethanol. At the same time, the structure of the aggregates became more friable, indicating the solvent effect of ethanol. The interaction force measurements showed that the adhesion force of fullerenes to the substrate decreased with increasing ethanol concentration, indicating a weakening of adhesion and molecular interactions. These data confirm the significant effect of ethanol on the physicochemical properties of fullerenes and can be used to develop nanomaterials with variable structural characteristics.

Investigation of the electrical properties and carrier concentration in n- and p-doped germanium

Galina Troshina, Natalya Voronena — Mon, 25 Dec 2023 00:00:00 +0600

This study investigates the Hall effect in n- and p-doped germanium samples through experimental measurements of Hall voltage, electrical conductivity, charge carrier mobility, and carrier concentration under varying magnetic fields and temperatures. The experimental setup involved measuring Hall voltage as a function of control current, magnetic field induction, and temperature using a TSE Co, LTD company Hall-effect unit. The linear dependence of the Hall voltage on the magnetic field was confirmed, yielding regression line slopes of b = 0.144 VT⁻¹± 0.004 VT⁻¹ for n-germanium and b = 0.125VT⁻¹ ± 0.003VT⁻¹for p-germanium. Corresponding Hall constants were calculated as R_H = 4.8×10 m^-3/C and R_H = 4.17×10 m^-3/C. Electrical conductivities were determined as σ = 53.6 S/m for n-germanium and σ = 57.14 S/m for p-germanium. The Hall mobilities were found to be μ_H = 0.257±0.005 m²/Vs for n-germanium and μ_H= 0.238±0.005 m²/Vs for p-germanium. Carrier concentrations were n = 13.0×10²⁰ m⁻³ for electrons and n =14.9×10²⁰ m⁻³ for holes. From temperature-dependent measurements, the energy bandgaps were calculated as E_g = 0.50 ± 0.04 eV for n-germanium and Eg = 0.72 ± 0.03 eV for p-germanium. The experimental findings provide comprehensive insights into the electronic properties of doped germanium, highlighting its behavior under magnetic fields and varying temperatures, with precise parameter evaluation crucial for semiconductor applications.

Spectroscopic analysis of α-particle emission from 241Am and 226Ra sources

Tatiana Timoshinova, Alexander Afanasyev — Tue, 26 Dec 2023 00:00:00 +0600

This paper investigates the energy spectra of α-particles emitted by radioactive sources ²⁴¹Am and ²²⁶Ra using a multichannel analyzer. Calibration of the detection system was performed with the primary peak of ²⁴¹Am at 5486 keV, yielding a sensitivity of S = 0.4631 mV/keV. The energy dependence on channel number was established, ensuring accurate energy characterization of the measured spectra. The effect of air pressure on α-particle spectra was analyzed by varying the pressure from vacuum to 500 hPa and 1000 hPa. Results demonstrated a systematic shift of the main peak position towards lower channels due to energy losses in the air, accompanied by peak broadening. For ²⁴¹Am, the primary peak shifted from approximately channel 2500 in vacuum to channels 2200 and 2000 at 500 hPa and 1000 hPa, respectively. The peak broadening increased linearly with energy loss, described by the relationship q = 0.073 ⋅ ΔE + 24.2 keV, where the constant 24.2 keV represents the intrinsic resolution of the detector. Comparative analysis of ²⁴¹Am and ²²⁶Ra spectra revealed the simpler structure of ²⁴¹Am, characterized by a single primary peak, versus the more complex, multi-component spectrum of ²²⁶Ra, which reflects contributions from daughter nuclides. Despite this complexity, the detector successfully captured the overall profile of ²²⁶Ra. These findings confirm the high precision of the detection system in measuring α-particle spectra under varying experimental conditions and highlight its potential for further studies of α-radiation interactions and the development of advanced detector technologies.

Investigation of splitting of a beam of potassium atoms in the classical Stern-Gerlach experiment at varying inhomogeneity of the magnetic field

Assel Akhmetova — Sun, 29 Dec 2024 00:00:00 +0500

The splitting of a beam of potassium atoms in the classical Stern-Gerlach scheme under varying inhomogeneity of the magnetic field is experimentally investigated in this work. First, the basic shape of the beam in the absence of an effective field is recorded, which makes it possible to introduce and calibrate the geometrical parameters of the channel. Then, when the current in the magnet windings increases and the field gradient grows, a systematic shift of the beam density maxima is observed, described by the model function F(u), which includes the parameter q, which characterizes the strength of interaction of atoms with the field. Theoretical calculations based on this function showed good agreement with the experimental results, including the asymmetry of the distribution due to the nonideal symmetry of the magnetic system. The obtained dependences of the position of the intensity maxima on ∇B confirmed the validity of both linear and asymptotic approximation for different modes of magnet operation. These conclusions have both fundamental importance for understanding the quantum mechanical aspects of beam splitting and applied significance in the development of methods for precise control of spin-polarized atomic beams in spectroscopy and spintronics.