Brazilian Journal of Physics最新文献

{"title":"Number Density and Abundance of Atoms and Ions in the Channel Plasma of Lightning","authors":"Xiaozhi Shen,&nbsp;Zhaoguang Gao,&nbsp;Huaming Zhang,&nbsp;Huaying Wang,&nbsp;Cuicui Sang","doi":"10.1007/s13538-025-01859-x","DOIUrl":"10.1007/s13538-025-01859-x","url":null,"abstract":"<div><p>Based on the Boltzmann distribution in local thermodynamic equilibrium, the partition functions for N I, N II, N III, and N IV and O I, O II, O III, and O IV were investigated by including highly excited energy levels. Through adding the Debye corrections into the Saha equation, the particle number density for air plasma was studied for various electron temperature (<span>(T_e)</span>) and electron density (<span>(n_e)</span>) by about 10,000–40,000 K and 5<span>(times )</span>10<span>(^{15})</span>–10<span>(^{21})</span> cm<span>(^{-3})</span>. Then, the corresponding abundance for air plasma was gained. Moreover, the changing tendency of particle number density and abundance in air plasma were applied to a lightning plasma when combined with its spectral diagnosis on <span>(T_e)</span> and <span>(n_e)</span>. The measured particle number density for N I, N II, N III, O I, and O II, separately, are 1.20<span>(times )</span>10<span>(^{16})</span>, 4.08<span>(times )</span>10<span>(^{17})</span>, 6.74<span>(times )</span>10<span>(^{15})</span>, 4.72<span>(times )</span>10<span>(^{15})</span>, and <span>(8.82times 10^{16}; text {cm}^{-3})</span> together with their measured abundance by about 2.31%, 78.46%, 1.29%, 0.91%, and 16.96%, respectively. Good consistency can be found in the comparison with other experiments.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145037412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elasticity of Irida-Graphene-Based and Sun-Graphene-Based Nanotubes: A Study by Fully Atomistic Reactive Classical Molecular Dynamics Simulations","authors":"Reza Kalami,&nbsp;J. M. De Sousa,&nbsp;Seyed Ahmad Ketabi","doi":"10.1007/s13538-025-01893-9","DOIUrl":"10.1007/s13538-025-01893-9","url":null,"abstract":"<div><p>In this work, we present a theoretical investigation of the elasticity properties of new exotic carbon allotropes studied recently, called Irida-graphene and Sun-graphene. Despite being theoretically studied in single-layer (2<i>D</i>), a study of the elastic properties of Irida-CNTs and Sun-CNTs has not yet been performed. Thus, we seek to investigate the elastic properties of nanotubes of these new exotic allotropes of carbon in quasi-one-dimensional geometry (1<i>D</i>), nanotubes for different chiralities, diameters, and lengths at room temperature. Our theoretical results obtained in the computational simulation show that the values of Young’s modulus for Irida-CNTs are in a slightly larger range (640.34 GPa - 825.00 GPa), while the Young’s modulus range of Sun-CNTs is 200.44 GPa - 472.84 GPa, lower values than those presented for conventional carbon nanotubes (CNTs). Our results also show the magnitude of Poisson’s ratio for Irida-CNTs and Sun-CNTs from the relative of nanotube bending and stretch, where the Poisson’s ratios are positive. For Irida-CNT, <span>(nu = 0.86-0.98)</span>, and for Sun-CNT, <span>(nu = 1.34-1.64)</span>. This tunability of Poisson’s ratio can be exploited in the design of nanotube-derived composites, artificial muscles, gaskets, and chemical and mechanical sensors. These findings provide insights into the nanomechanical behavior of Irida-CNTs and Sun-CNTs and their potential applications in nanoscale devices.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145021557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating Charge Radius and Spin–Orbit Effects in Sn Isotopes Using Density Functional Theory","authors":"Hossein Sadeghi,&nbsp;Mahdieh Ghafouri","doi":"10.1007/s13538-025-01895-7","DOIUrl":"10.1007/s13538-025-01895-7","url":null,"abstract":"<div><p>The energy density functional (EDF) theory is an essential microscopic approach used in theoretical nuclear physics to study the nuclear structure of heavy nuclei on a large scale. In this research, density functional theory (DFT) solvers were utilized to solve self-consistent equations for both spherical and deformed shapes. The effects of spin–orbit density, energy, and charge radius of Sn isotopes were analyzed using the Skyrme Hartree Fock (SHF) and Skyrme Hartree Fock Bogolyubov (SHFB) methods, which take into account pairing interactions that vary with density. The calculated radius for both spherical and deformed states was compared to experimental data to evaluate the influence of deformation. These comparisons are usually performed using the Hartree Fock Bogolyubov (HFB) or the Hartree Fock BCS (HFBCS) method. The consistency of our findings with those obtained from the spherical RMF(Relativistic Mean-Field)-PC code strengthens the reliability of our conclusions. These results are significant as they allow for an accurate assessment of the force distribution within uniform spherical Nuclei.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Study of the Effect of Metal Change on the Structural, Electronic, and Optical Properties of Perovskites [NH3(CH2)4NH3]MCl4 (M = Co, Cd): Optoelectronic Applications","authors":"Sana Mazouar,&nbsp;Hafida Ziouani,&nbsp;Ilyas Chabri,&nbsp;Abdelilah Taoufik,&nbsp;El Mostafa Khechoubi,&nbsp;Mahmoud Ettakni","doi":"10.1007/s13538-025-01884-w","DOIUrl":"10.1007/s13538-025-01884-w","url":null,"abstract":"<div><p>Organic–inorganic hybrid perovskites (OIHP) are currently the subject of rigorous study due to their promising utility in optoelectronics and photovoltaics. Therefore, in this work, we perform an in-depth analysis of OIHP perovskites, in particular [NH₃(CH₂)₄NH₃]MCl₄ (M = Co, Cd). We focus on structural, electronic, and optical properties and present information on this subject for the first time. Our study revealed the stable triclinic phase structure of the hybrid [NH₃-(CH₂)₄-NH₃]CoCl₄ and monoclinic of the hybrid [NH₃-(CH₂)₄-NH₃]CdCl₄ perovskites, with calculated free energies of − 10522.91 eV and − 10520.13 eV, corresponding to a relative stability difference of approximately 2.78 eV, respectively indicating their structural robustness. The semiconducting characteristics of [NH₃(CH₂)₄NH₃]CoCl₄ and [NH₃(CH₂)₄NH₃]CdCl₄ are highlighted by their wide indirect band gaps of 1.84 eV and 0.88 eV, respectively. We then examine the optical parameters, including the dielectric function, absorption coefficient, optical conductivity, refractive index, and energy loss function. Our results highlight the exceptional ability of these materials to absorb ultraviolet radiation in the electromagnetic spectrum, making them promising candidates for optoelectronic applications. The outcomes of our research catalyze deeper inquiry into the application of these materials in technologically significant contexts. Calculations were performed using a first-principles approach based on density functional theory (DFT). The electronic properties of the system were examined using the HSE06 hybrid exchange–correlation function and the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) within the CASTEP framework. Within this framework, Kramers–Kronig relations are used to obtain crucial optical parameters.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction Note: Green Synthesis and Photocatalytic and Antibacterial Performance of Cerium and Silver Dual Doped ZnO Nanoparticles","authors":"Fuád Ameén,&nbsp;Hosséin Khonakbaar,&nbsp;Pézhman Narany","doi":"10.1007/s13538-025-01872-0","DOIUrl":"10.1007/s13538-025-01872-0","url":null,"abstract":"","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional Properties of Rare Earth Doped AlXO₂ Delafossites for Energy Applications","authors":"N. M. A. Hadia,&nbsp;Meshal Alzaid,&nbsp;M. F. Hasaneen,&nbsp;W. S. Mohamed,&nbsp;Muhammad Irfan,&nbsp;Emad M. Ahmed,&nbsp;Hesham M. H. Zakaly","doi":"10.1007/s13538-025-01887-7","DOIUrl":"10.1007/s13538-025-01887-7","url":null,"abstract":"<div><p>Cu-based delafossite compounds AlXO₂ (X = Cu, Eu, Er) have emerged as technologically important materials for optoelectronic applications due to their unique combination of p-type conductivity and tunable electronic properties. Our comprehensive investigation reveals that these materials exhibit small direct band gaps ranging from 1.2 to 1.8 eV, ideal for solar energy conversion. First-principles calculations demonstrate strong p-d hybridization, characterized by exchange constants N₀β = − 0.19, − 0.12, − 0.14 and N₀α = 0.16, 0.24, 0.31 for Cu, Eu, and Er variants, respectively, indicating dominant exchange field contributions to their magnetic behavior. Optical property analysis in the 0–14 eV range shows significant anisotropy in absorption coefficients and dielectric functions, with notable birefringence effects. Remarkably, these materials demonstrate hydrogen storage capacities of 4.5–5.48 wt%, while thermoelectric calculations predict a figure of merit (ZT) of 0.55 at 600 K. The synergistic combination of favorable optoelectronic properties, magnetic tunability, and energy storage capabilities positions these delafossites as promising candidates for next-generation photovoltaic, spintronic, and energy storage applications. These findings provide fundamental insights into structure–property relationships in ternary oxides while demonstrating their potential for multifunctional device applications.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144927158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Temperature and Magnetic Field on the Magnetic Structure of Domains of the Fe5Ga6Gd2YZr Crystal","authors":"Nargiza Gayratovna Nasirova,&nbsp;Shaxobiddin Shavkatovich Fayziyev,&nbsp;Qurbon Sayfullayevich Saidov,&nbsp;Bashorat Eshmamatovna Niyazxonova,&nbsp;Davron Raxmonovich Dzhuraev","doi":"10.1007/s13538-025-01874-y","DOIUrl":"10.1007/s13538-025-01874-y","url":null,"abstract":"<div><p>This study examines the X-ray fluorescence spectroscopy results and Raman scattering spectroscopy results of a Fe₅Ga₆Gd₂YZr crystal. A quantitative analysis of the spectral data was conducted. Raman spectroscopy and X-ray fluorescence (XRF) analysis were employed to obtain spectral peaks, which were used to study the structural features and elemental composition of the sample, respectively, as part of its physical analysis. The graphs clearly show the intensities of the characteristic lines of the elements such as Fe, Ga, Gd, Y, and Zr. Additionally, the temperature dependence of domain structure ordering in the Fe₅Ga₆Gd₂YZr crystal was investigated over the range of 134–296 K. The study demonstrated that temperature-induced changes in the domain structure led to the emergence of magnetic hysteresis. It was observed that as the temperature rises, the separation between domain boundaries gets wider. Moreover, the effect of an external magnetic field on the domain structure was studied in the magnetic induction interval of 0–4.6 mT. Comparative analysis of domain images under increasing and decreasing magnetic field conditions clearly illustrates the presence of remanent magnetization within the crystal.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144914568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlating Local Quantum Reality with Causally Disconnected Choices","authors":"D. S. Starke,&nbsp;J. Maziero,&nbsp;R. M. Angelo","doi":"10.1007/s13538-025-01894-8","DOIUrl":"10.1007/s13538-025-01894-8","url":null,"abstract":"<div><p>In 1935, Einstein, Podolsky, and Rosen (EPR) claimed the incompleteness of quantum mechanics based on the notions of realism (“<i>If, without in any way disrupting a system, we can predict with certainty - i.e., with a probability of one - the value of a physical quantity, then an element of physical reality corresponds to this physical quantity.</i>”) and locality (“<i>... since the two systems no longer interact, no real change can take place in the second system in consequence of anything that may be done to the first system</i>”). EPR also insisted that “<i>The elements of physical reality cannot be determined by </i>a priori<i> philosophical considerations, but must be found by ... experiments and measurements.</i>” Here, employing an operational framework for testing realism in quantum systems, we envisage an experiment—referred to as the Reality Quantum Correlator (RQC)—capable of showing that the elements of reality in one laboratory can be correlated with causally disconnected choices, thus questioning EPR’s locality. Empirical evidence supporting our theoretical predictions is then provided by implementing the corresponding quantum circuit on IBM’s quantum computers.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144914549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elastic, Electronic, Thermal and Superconducting Properties of Ni-Based Borocarbides MNi2B2C (M = Sc, Y, La, Yb, Lu, Th) through DFT Replication","authors":"Md. Atikur Rahman,&nbsp;Norah Algethami,&nbsp;Mst. Asma Khatun,&nbsp;Mohammad Yasin Hayat Khan,&nbsp;Md. Nadim Mahamud Nobin,&nbsp;Tajrin Akhtar,&nbsp;Ananya Basak","doi":"10.1007/s13538-025-01881-z","DOIUrl":"10.1007/s13538-025-01881-z","url":null,"abstract":"<div><p>To explore the mechanical, electronic, thermal, and superconducting features of Ni-based borocarbide materials MNi₂B₂C (M = Sc, Y, La, Yb, Lu, Th); the Density Functional Theory (DFT) is employed accomplished with CASTEP code. The crystal structures of these materials were relaxed via the Generalized Gradient Approximation (GGA). The grounded lattice parameters reveal healthy settlement with the experimental values. We have assured about the dynamical stability of MNi₂B₂C (M = Sc, Y, La, Yb, Lu, Th) from the positive phonon dispersion curvatures. The materials MNi₂B₂C (M = Sc, Y, La, Yb, Lu, Th) display mechanical stability as the premeditated elastic constants hold the Born constancy standards. The moderately resisting behavior of these phases to the external forces has been confirmed by the analysis of Young’s, shear and bulk moduli. Analysis of Pugh’s (<i>B</i>/<i>G</i> &gt; 1.75) and Poisson’s ratios (υ &gt; 0.26) ensures the ductile manner of MNi₂B₂C (M = Sc, Y, La, Yb, Lu, Th) whereas soft nature is confirmed from hardness (<i>H</i>_v) analysis. The significant use as coating materials of these materials is assured from the high values of machinable index (<i>µ</i>_m). The metallic nature and existing of several chemical bonding including ionic as well as covalent bonds are confirmed from electronic properties analysis. The thermal barrier covering manner of MNi₂B₂C (M = Sc, Y, La, Yb, Lu, Th) is also assured from high melting temperature and exceedingly low thermal conductivity values. The reasonable thermal conductive nature of MNi₂B₂C (M = Sc, Y, La, Yb, Lu, Th) is ensured from the values of Debye temperature (<i>θ</i>_D). Analysis of superconducting properties ensures that the titled borocarbide materials contain low transition temperature (<i>T</i>_c) which are good accord with the experimental values.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144914550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Ceria Nanoparticle Properties Through Neodymium Doping: A Comprehensive Study","authors":"Handan Özlü Torun,&nbsp;Nurvet Kırkgeçit Aksoy,&nbsp;Fatma Kılıç Dokan","doi":"10.1007/s13538-025-01863-1","DOIUrl":"10.1007/s13538-025-01863-1","url":null,"abstract":"<div><p>Efficient energy storage is essential for sustainable technological development, with supercapacitors emerging as a promising solution due to their high power density and long cycle life. To enhance their electrochemical performance, the discovery and optimization of advanced electrode materials are critical. Cerium oxide (CeO₂) has recently gained attention, particularly when doped with rare-earth elements such as neodymium (Nd). This study investigates the structural, morphological, and electrochemical properties of Nd-doped CeO₂ synthesized via the glycine combustion method with Nd concentrations of 3, 6, and 9 mol%. Crystalline structure was characterized using X-ray diffraction (XRD), Rietveld refinement, and Raman spectroscopy. All samples exhibited a face-centered cubic (fcc) lattice, and Raman analysis confirmed that Nd incorporation maintained the structural integrity while inducing oxygen vacancies. Morphological analysis via field emission scanning electron microscopy (FESEM-EDS) and Brunauer–Emmett–Teller (BET) measurements revealed nanoparticles with sizes below 100 nm and uniform elemental distribution aligned with the target doping levels. Electrochemical behavior was assessed through cyclic voltammetry. The 3 mol% Nd-doped CeO₂ sample demonstrated the highest specific capacitance of 40 F g⁻¹, attributed to its optimized defect structure and enhanced surface characteristics. These findings suggest that Nd-doped CeO₂, particularly at low doping concentrations, holds significant promise as an efficient electrode material for next-generation supercapacitor applications.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}