International Journal of Physics | Vol. 15, No. 6, June 2024 | pp. 41–48
DOI: 10.46882/2024/IJP/000170
Research Article
Title: Superconducting Phase Transitions and Magnetic Flux Dynamics in Niobium-Carbon Thin Films
Names of Authors: O. K. Semenov¹, Y. S. Kim²
Authors’ Affiliations:
¹ Institute for Solid State Physics, Russian Academy of Sciences, Moscow, Russia
² Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
Abstract: Stabilizing the magnetic vortex lattice and maximizing the critical current capacity of superconducting layers under strong applied magnetic fields are vital for engineering single-photon sensors and high-field laboratory magnets. This study evaluates the superconducting phase transitions and maps magnetic flux pinning configurations in niobium-carbon (Nb-C) thin films. The thin films were prepared via magnetron sputtering on sapphire substrates with thickness parameters ranging from 50.0 nm to 300.0 nm. We conducted low-temperature electrical transport and magnetometry profiles across a temperature grid from 1.5 K to 15.0 K under magnetic fields up to 10.0 T. The pristine 300.0 nm film displayed a sharp superconducting transition with a critical temperature (Tc) of 11.2 K at zero field. Magnetization loops revealed a high critical current density (Jc) exceeding 4.2 x 10^6 A/cm² at 4.2 K. Analysis of the pinning force density indicates that introducing nanoscale carbon inclusions triggers an intensive vortex-locking matching effect. The upper critical field, Hc2(0), was estimated to be 14.5 T using the Werthamer-Helfand-Hohenberg model, proving that grain boundary control improves layer performance.
Keywords: Superconductivity; thin films; flux pinning; critical current density; upper critical field; magnetron sputtering
Manuscript Timeline: Received: March 02, 2024; Revised: April 14, 2024; Accepted: May 02, 2024; Published: June 18, 2024
Citation: Semenov, O. K., & Kim, Y. S. (2024). Superconducting Phase Transitions and Magnetic Flux Dynamics in Niobium-Carbon Thin Films. International Journal of Physics, 15(6), 41–48.
International Journal of Physics | Vol. 15, No. 5, May 2024 | pp. 33–40
DOI: 10.46882/2024/IJP/000169
Research Article
Title: Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Core-Shell Nanowire Interfaces
Names of Authors: M. G. Richter¹, D. W. Meyer²
Authors’ Affiliations:
¹ Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
² Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany
Abstract: Restricting cross-interface thermal transport across mismatched semiconductor boundaries is a primary technical challenge when engineering next-generation high-efficiency thermoelectric harvesters and protecting microcircuit nodes from hotspot deterioration. This paper uses molecular dynamics simulations to quantify thermal dispersion metrics and track phonon wavepacket scattering at defective silicon-silicide (Si-NiSi2) core-shell nanowire boundaries. We constructed atomistic structural configurations using the optimized Stillinger-Weber empirical potentials, incorporating varying concentrations of interfacial point defects and shell thickness variations. Longitudinal and transverse acoustic phonon wavepackets were launched with narrow frequency spreads centered between 2.0 THz and 8.0 THz. The computational data demonstrate that high-frequency acoustic phonons (f greater than 5.2 THz) undergo strong diffuse scattering at the rough interface, dropping the calculated transmission coefficient from 0.84 down to 0.20. This transport degradation is driven by localized strain fields and interface-bound vibrational modes. The overall interfacial thermal conductance decreased by 50.0% when the interface roughness parameter scaled from 0.1 nm to 0.6 nm at 300.0 K, revealing structural constraints for nanoscale device design.
Keywords: Thermal dispersion; phonon wavepacket; molecular dynamics; core-shell nanowires; thermoelectric cooling; silicide interfaces
Manuscript Timeline: Received: February 11, 2024; Revised: March 24, 2024; Accepted: April 10, 2024; Published: May 15, 2024
Citation: Richter, M. G., & Meyer, D. W. (2024). Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Core-Shell Nanowire Interfaces. International Journal of Physics, 15(5), 33–40.
International Journal of Physics | Vol. 15, No. 4, April 2024 | pp. 25–32
DOI: 10.46882/2024/IJP/000168
Research Article
Title: Relativistic Hydrodynamic Simulations of Particle Generation Cascades in Asymmetric Argon-Gold Collisions
Names of Authors: H. L. Mueller¹, S. C. O’Brien²
Authors’ Affiliations:
¹ Institut für Kernphysik, Karlsruher Institut für Technologie, Karlsruhe, Germany
² School of Physics, University College Dublin, Dublin, Ireland
Abstract: High-energy asymmetric heavy-ion collisions provide a vital experimental testing ground for decoupling localized cold nuclear matter parameters from collective hot quark-gluon plasma behaviors in intermediate configurations. This study presents a relativistic hydrodynamic modeling framework to simulate particle production cascades during asymmetric argon-gold (Ar-Au) collisions at a center-of-mass energy of 200.0 GeV per nucleon pair. We utilized a 3+1 dimensional viscous hydrodynamic code coupled with a statistical hadronization module to compute transverse momentum spectra and azimuthal anisotropy coefficients. The initial energy density distributions were generated via a Glauber-Gribov color-fluctuation model to track localized sub-nucleon scale features. The numerical simulations show that expanding fireballs develop a substantial radial flow profile, shifting the mean transverse momentum of protons up to 1.42 GeV/c in central runs. The calculated elliptic flow coefficient (v²) displays a strong mass-ordering signature, which matches experimental measurements gathered by specialized forward tracking spectrometers within a tight ±6.0% margin. This close agreement implies that small-scale systems can achieve brief collective hydrodynamic expansion.
Keywords: Relativistic hydrodynamics; particle production; argon-gold collisions; elliptic flow; color-fluctuation model; statistical hadronization
Manuscript Timeline: Received: January 08, 2024; Revised: February 17, 2024; Accepted: March 09, 2024; Published: April 10, 2024
Citation: Mueller, H. L., & O’Brien, S. C. (2024). Relativistic Hydrodynamic Simulations of Particle Generation Cascades in Asymmetric Argon-Gold Collisions. International Journal of Physics, 15(4), 25–32.
International Journal of Physics | Vol. 15, No. 3, March 2024 | pp. 17–24
DOI: 10.46882/2024/IJP/000167
Research Article
Title: Kinetic Simulation of Electron Drift Mechanics and Radical Yields in Trifluoromethane Discharges
Names of Authors: A. M. El-Chemali¹, S. H. Zhang²
Authors’ Affiliations:
¹ Department of Physics, Faculty of Science, Lebanese University, Beirut, Lebanon
² Department of Physics, Tsinghua University, Beijing, China
Abstract: Trifluoromethane (CHF3) gas discharges are widely utilized across the microelectronics manufacturing industries for precision dielectric oxide etching, chamber surface passivation, and thin-film texturing. This study develops a self-consistent kinetic simulation model to analyze electron drift mechanics and compute radical generation rates in low-pressure CHF3 discharges. We solved the electron Boltzmann equation using a multi-term spherical harmonic expansion framework across an expansive reduced electric field range (E/N) spanning 10.0 Td to 600.0 Td. The model incorporates comprehensive cross-section sets detailing elastic collision momentum transfers, vibrational pumping thresholds, dissociative attachment, and electron-impact ionization tracks. Our calculations demonstrate that adding helium diluents (from 20.0% to 70.0% by volume) significantly distorts the high-energy tail of the electron energy distribution function. At a field strength of E/N = 60.0 Td, the total CF2 radical production rate coefficient scales up by an order of magnitude due to enhanced electron mean energies. The calculated electron drift velocities match independent swarm experimental tracks within a tight ±4.5% variance index, providing vital baseline constants for optimization.
Keywords: Trifluoromethane; Boltzmann equation; electron transport; plasma kinetics; cross-section; dielectric etching
Manuscript Timeline: Received: December 14, 2023; Revised: January 20, 2024; Accepted: February 08, 2024; Published: March 13, 2024
Citation: El-Chemali, A. M., & Zhang, S. H. (2024). Kinetic Simulation of Electron Drift Mechanics and Radical Yields in Trifluoromethane Discharges. International Journal of Physics, 15(3), 17–24.
International Journal of Physics | Vol. 15, No. 2, February 2024 | pp. 9–16
DOI: 10.46882/2024/IJP/000166
Research Article
Title: High-Pressure Mechanical Attributes and Elastic Anisotropy Indices of Ultra-Incompressible Titanium Tetraboride
Names of Authors: V. I. Morozov¹, I. R. Sokolov²
Authors’ Affiliations:
¹ Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia
² Kapitza Institute for Physical Problems, Russian Academy of Sciences, Moscow, Russia
Abstract: Synthesizing ultra-hard, incompressible refractory configurations capable of resisting intense mechanical shearing and structural deformation under high stress is essential for advancing ballistic shielding and aerospace industrial tooling. This paper examines high-pressure mechanical attributes and quantifies elastic anisotropy indices in orthorhombic titanium tetraboride (TiB4) up to hydrostatic loads of 150.0 GPa. We performed first-principles density functional theory computations incorporating generalized gradient approximations across systematically compressed lattice grids. At zero pressure, the calculated bulk modulus is B0 = 286.0 GPa, with an elastic pressure derivative coefficient of B0' = 4.14, matching experimental diamond anvil cell recordings within a tight 1.2% margin. The single-crystal elastic constants (C11, C22, C33, C44, C55, and C66) climb monotonically under compression, strictly satisfying all Born mechanical stability parameters across the complete pressure range. The directional compressibility curves reveal that the crystal c-axis displays exceptional stiffness due to short, covalent titanium-boron bonds interlocking the structural rows. Electronic band-structure maps verify a high density of states at the Fermi boundary, indicating that TiB4 retains its metallic character under high stress.
Keywords: Titanium tetraboride; density functional theory; elastic constants; high pressure; mechanical stability; directional compressibility
Manuscript Timeline: Received: November 02, 2023; Revised: December 18, 2023; Accepted: January 11, 2024; Published: February 14, 2024
Citation: Morozov, V. I., & Sokolov, I. R. (2024). High-Pressure Mechanical Attributes and Elastic Anisotropy Indices of Ultra-Incompressible Titanium Tetraboride. International Journal of Physics, 15(2), 9–16.
International Journal of Physics | Vol. 15, No. 1, January 2024 | pp. 1–8
DOI: 10.46882/2024/IJP/000165
Research Article
Title: Resonant Energy Transfer Kinetic Profiles between Quantum Dots and Graphene Monolayers
Names of Authors: T. H. Nguyen¹, M. G. Richter²
Authors’ Affiliations:
¹ Department of Physics, Vietnam National University, Hanoi, Vietnam
² Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
Abstract: Hybrid low-dimensional semiconductor frameworks combine zero-dimensional and two-dimensional characteristics to enable advanced light-harvesting systems, nanoscale optical pathways, and highly adaptive optoelectronic switches. This paper evaluates non-radiative Förster resonant energy transfer (FRET) dynamics between colloidal cadmium selenide (CdSe) quantum dots and pristine chemical vapor deposition graphene monolayers. The hybrid interfaces were fabricated via sequential layer deposition routines onto high-purity quartz substrates. We performed steady-state photoluminescence and time-resolved single-photon counting tracks at an operating temperature of 300 K. The experimental measurements reveal a profound 84.0% quenching of the quantum dot photoluminescence emission when phase-coupled to the graphene sheets. Concurrently, the average fluorescence lifetime of the CdSe quantum dots decreased from 5.2 ns down to 0.83 ns. This lifetime shortening yields a calculated FRET efficiency of 84.0% with a corresponding energy migration rate of 1.01 ns⁻¹. The donor-acceptor boundary separation distance was determined to be 3.6 nm using the standard mathematical equations of the Förster model. These rapid near-field energy dynamics provide core physical data for designing hyper-sensitive thin-film photodetectors.
Keywords: Quantum dots; graphene; resonant energy transfer; fluorescence lifetime; hybrid nanostructures; optoelectronics
Manuscript Timeline: Received: October 12, 2023; Revised: November 24, 2023; Accepted: December 15, 2023; Published: January 15, 2024
Citation: Nguyen, T. H., & Richter, M. G. (2024). Resonant Energy Transfer Kinetic Profiles between Quantum Dots and Graphene Monolayers. International Journal of Physics, 15(1), 1–8.