Brazilian Journal of Physics最新文献

{"title":"A New Approach to Humidity Sensors Using Titanium Trisulfide (TiS3) Nanoribbons","authors":"Atiye Engashte,&nbsp;Zahra Sadat Hosseini,&nbsp;Shahrokh Ahmadi,&nbsp;Hanie Dalvand,&nbsp;Amir Ali Masoudi","doi":"10.1007/s13538-025-01900-z","DOIUrl":"10.1007/s13538-025-01900-z","url":null,"abstract":"<div><p>Humidity sensors play a critical role in diverse applications. Therefore, high-performance humidity sensors based on titanium trisulfide (TiS₃) nanoribbons (NRs) were developed. TiS₃ NRs were synthesized and characterized thoroughly using morphological, structural, and chemical compositional techniques. Then, the humidity sensing performance of the fabricated TiS₃-based sensor was systematically evaluated. Key findings include a sensitivity of 0.50 kΩ/%RH, a relatively short response and recovery time of approximately 21 s and 12 s, respectively, along with excellent long-term stability, low hysteresis (1.96% RH), high repeatability, and reproducibility. The performance of TiS₃ NRs-based sensors in practice was tested using exhaled breath, and the results were satisfactory. The sensing mechanism is attributed to the adsorption and condensation of water molecules on the layered TiS₃ surface, followed by the formation of a conductive path by water molecules at high RH. The results underscore the significant potential of TiS₃ as a robust material for highly sensitive and stable humidity sensors.\u0000</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078902","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":"Size-Dependent Dispersion and Slow-Light Effects in CdS@Ag Core-Shell Quantum Dots: A Theoretical Study of Plasmonic Resonances and Group Velocity Modulation","authors":"Shewa Getachew Mamo","doi":"10.1007/s13538-025-01906-7","DOIUrl":"10.1007/s13538-025-01906-7","url":null,"abstract":"<div><p>This study investigates the size-dependent dispersion and slow-light phenomena in CdS@Ag core-shell quantum dot nanostructures embedded within various dielectric host materials. A comprehensive theoretical framework is developed by integrating the Maxwell-Garnett effective medium theory with the electrostatic approximation, alongside a size-corrected Drude model to characterize the metallic shell. This approach enables the accurate modeling of the effective dielectric function, polarizability, refractive index, and group velocity. Numerical simulations are conducted across a range of core radii, shell thicknesses, and host permittivities to systematically examine the influence of geometrical and environmental parameters on plasmonic resonances and pulse propagation dynamics. The results reveal two distinct, tunable surface plasmon resonances at the CdS/Ag and Ag/host interfaces, whose hybridization significantly alters the refractive index dispersion. Pronounced slow-light effects are observed in proximity to these resonances, including a reduction in group velocity by more than an order of magnitude and the emergence of negative group velocity regimes. These findings offer valuable insights into the geometry- and environment-dependent plasmon-exciton coupling mechanisms in core-shell quantum dots and provide guiding principles for the design of advanced nanophotonic devices such as optical delay lines, modulators, and plasmon-enhanced sensors.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078901","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":"Comprehensive Assessment of 2-(3-Methoxyphenylamino)-2-Oxoethyl Methacrylate: Spectroscopic, Computational, Toxicological, Molecular Docking and Dynamic Studies with STAT3 Protein","authors":"Nevin Çankaya,&nbsp;Mehmet Hanifi Kebiroğlu,&nbsp;Serap Yalcin Azarkan","doi":"10.1007/s13538-025-01888-6","DOIUrl":"10.1007/s13538-025-01888-6","url":null,"abstract":"<div><p>In this study, we successfully resynthesized the compound 2-(3-methoxyphenylamino)-2-oxoethyl methacrylate (3MPAEMA) and characterized it using experimental spectroscopic methods and advanced computational analyses. Theoretical investigations encompassed Natural Bond Orbital (NBO) analysis, Band Gap (BG) calculations, Molecular Electrostatic Potential (MEP) mapping, and Density of States (DOS) evaluations, offering a comprehensive understanding of the molecule's electronic structure. We also employed thermochemical parameters, electronic descriptors, and Non-Covalent Interaction (NCI) analyses to assess the compound’s stability, reactivity, and intramolecular interactions. We performed toxicological profiling through in silico oral toxicity prediction models, validating model performance metrics. We conducted molecular docking and 50-ns molecular dynamics (MD) simulations to elucidate the binding behavior of 3MPAEMA with the oncogenic transcription factor STAT3, specifically targeting its SH2 domain. Docking studies revealed a strong binding affinity, while MD simulations confirmed the structural stability of the 3MPAEMA–STAT3 complex. Collectively, these results underscore the promising potential of 3MPAEMA as a STAT3-targeting agent in anticancer therapy. However, further in vitro and in vivo investigations must confirm its therapeutic potential. This comprehensive study offers valuable insights into the physicochemical, toxicological, and biological attributes of 3MPAEMA, supporting its candidacy for future biomedical applications.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078900","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":"Dispersive Monotonic and Oscillatory Shock Wave Structures in Magnetized Quantum Plasma with Arbitrary Degeneracy of Electrons","authors":"Sajjad Hussain,&nbsp;Naseem Akhtar,&nbsp;Hafeez Ur-Rehman","doi":"10.1007/s13538-025-01903-w","DOIUrl":"10.1007/s13538-025-01903-w","url":null,"abstract":"<div><p>The propagation of magnetosonic, nonlinear monotonic, and oscillatory shock structures in a homogeneous plasma with arbitrary degeneracy of electrons is investigated using a quantum magneto-hydrodynamic model (QMHD). The ions are classical, and dissipation in the system is taken through their kinematic viscosity. The electrons are degenerate, and their quantum effects through Bohm potential term are included. The reductive perturbation method is used to study the energy transfer mechanism, and the nonlinear Korteweg–de Vries–Burgers (KdVB) equation is derived for arbitrary degenerate plasmas. The different solutions of the KdVB equation are presented for monotonic and oscillatory shock structures in the presence of degeneracy of electrons. The effects of chosen values of equilibrium fugacity, electron temperature, magnetic field, and the corresponding electron density of a physical quantum plasma system on the height (intensity) of the monotonic and oscillatory shock structures are pointed out. These findings may be helpful to understand the excitation of magnetosonic shock wave phenomena in astrophysical, space, and fusion plasmas.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073898","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":"Unveiling Electron-Phonon Effects on Thermodynamics of Bernal Bilayer Graphene in External Fields","authors":"Farshad Azizi,&nbsp;Hamed Rezania","doi":"10.1007/s13538-025-01904-9","DOIUrl":"10.1007/s13538-025-01904-9","url":null,"abstract":"<div><p>We investigate the influence of electron-phonon interactions on the thermodynamic properties of Bernal-stacked bilayer graphene under external magnetic fields, employing the Holstein model and Green’s function approach. By calculating the one-loop electronic self-energy within a full-band framework, we derive the interacting Green’s function to analyze the temperature-dependent behavior of specific heat and Pauli spin susceptibility, alongside the energy-dependent density of states (DOS). Our results reveal that increasing electron-phonon coupling reduces the peak height of specific heat while shifting its characteristic temperature to higher values. Similarly, stronger magnetic fields elevate the DOS at the Fermi level and induce Zeeman splitting, enhancing metallic behavior. Bias voltage variations widen the band gap, reinforcing semiconducting characteristics. These findings highlight the critical role of electron-phonon interactions and external fields in tailoring the electronic and thermodynamic properties of bilayer graphene, offering insights for advanced material applications.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073678","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":"Hydrothermally Synthesized Nano Ba2SnO4 Ternary Metal Oxide: A Promising Material for Enhanced NO2 Gas Sensing","authors":"Sagar H Mane,&nbsp;Tushar S Wagh,&nbsp;Swapnil S Shendge,&nbsp;Amol B Rahane,&nbsp;Gotan H Jain,&nbsp;Madhavrao K Deore,&nbsp;Ganesh J Mogal","doi":"10.1007/s13538-025-01882-y","DOIUrl":"10.1007/s13538-025-01882-y","url":null,"abstract":"<div><p>In the present study, Ba₂SnO₄ nanostructures were synthesized via the hydrothermal method at 180 °C for 24 h, using 1 M BaCl₂ as the barium source and varying concentrations of SnCl₄ (0.1, 0.3, 0.5, and 0.7 M) as the tin precursor. Thick films of the resulting Ba₂SnO₄ nanomaterials were fabricated using the screen printing technique. The corresponding film thicknesses obtained for each SnCl₄ concentration were approximately 65, 58, 53 and 47 μm, respectively. The structural properties of Ba₂SnO₄ were confirmed by X-Ray diffraction and the formation of nano Ba₂SnO₄ where confirmed by transmission electron microscopy (TEM). The surface morphology and surface characteristics of fabricated material analyzed using scanning electron microscopy (SEM) while the energy dispersive spectroscopy analysis (EDS) shows the chemical composition of the prepared thick film. The fabricated thick films of various compositions were tested for different hazardous gases like Nitrogen dioxide (NO₂), Ammonia (NH₃), Hydrogen Sulphide (H₂S), Ethanol (C₂H₆O), and Methanol (CH₃OH). The thick film of Ba₂SnO₄ thick film prepared at molar concentration Ba (1 M): Sn (0.1 M) (Sample 1) shows the maximum sensitivity 69.88% to NO₂ gas at an operating temperature of 200 °C and concentration of 400 ppm. The rapid response and recovery were recorded for Ba₂SnO₄ thick film gas sensor.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073679","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":"Reinforcing the Structural, Dielectric, Conductivity, and Linear/Nonlinear Optical Properties of PS-Bi2O3-SiO2 Nanostructures for Radiation Protection and Optoelectronic Applications","authors":"Majeed Ali Habeeb,&nbsp;Idrees Oreibi,&nbsp;Rehab Shather Abdul Hamza,&nbsp;Mamoun Fellah,&nbsp;Noureddine Elboughdiri","doi":"10.1007/s13538-025-01902-x","DOIUrl":"10.1007/s13538-025-01902-x","url":null,"abstract":"<div><p>The objective of this work is to create innovative nanocomposite films by integrating nanostructures (bismuth oxide Bi₂O₃ and silicon dioxide SiO₂) into polystyrene (PS). The primary objective of this study was to examine the structural and optical characteristics of nanostructures made up of PS-Bi₂O₃-SiO₂. The FTIR spectra indicate the existence of a physical contact between the original polymer and nanoparticles. At a concentration of 6 wt.%, optical microscope findings indicate the formation of a cohesive network of (Bi₂O₃-SiO₂) nanoparticles inside the polymer matrix, which is different from the pure (PS) film. The optical properties of pure PS, such as extinction coefficient (K), absorption index (α), absorbance (A), refractive index (n), and optical conductivity(σ_op), showed a positive correlation with the higher concentration of (Bi₂O₃-SiO₂) nanoparticles. Thus, these findings indicate that the material may be appropriate for various optoelectronic devices, including solar cells, transistors, electronic gates, photovoltaic cells, lasers, diodes, and other related applications. The integration of nanoparticles leads to an increase in the third-order nonlinear susceptibility (χ⁽³⁾), linear susceptibility (χ⁽¹⁾), Urbach energy (E_u), average oscillator wavelength (λ_o), nonlinear refractive index (n₂), and static refractive index (n_o). Conversely, there is a noticeable reduction in the average oscillator strength (S_o), dispersion energy (E_d), and single-oscillator energy (E_osc). The analysis of the dielectric properties of (PS-Bi₂O₃-SiO₂) nanocomposites revealed that an increase in the concentration of (Bi₂O₃-SiO₂) nanoparticles resulted in a corresponding rise in the ε', ε\", and σ_a.c of pure PS. The PS-Bi₂O₃-SiO₂ nanocomposites show considerable gamma ray attenuation coefficients, according to the study. This paper suggests that these nanocomposites can be used in optoelectronic nanodevices and gamma radiation shielding.\u0000</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062198","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":"Effect of Chelating Agent Concentration on the Pseudocapacitive Performance of V2O5 Flakes Prepared by the Hydrothermal Process for Supercapacitor Applications","authors":"Sheik Abdul Sattar,&nbsp;Kilari Naveen Kumar,&nbsp;S K. Vinay,&nbsp;Kotian Akshata Chandrakant,&nbsp;G. V. Ashok Reddy,&nbsp;R Imran Jafri,&nbsp;Dhanalakshmi Radhalayam,&nbsp;Nunna Guru  Prakash,&nbsp;P. Rosaiah,&nbsp;Atif Mossad Ali,&nbsp;Tae Jo Ko","doi":"10.1007/s13538-025-01896-6","DOIUrl":"10.1007/s13538-025-01896-6","url":null,"abstract":"<div><p>Vanadium pentoxide (V₂O₅) flakes were synthesized via a hydrothermal method by varying the amount of lemon juice (5 mL for sample-1 and 10 mL for sample-2) as a natural chelating agent. Structural and morphological analyses were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), confirming crystalline V₂O₅ with flake-like morphologies influenced by chelating agent concentration. Electrochemical performance was evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a 3 M KOH electrolyte. Sample-2 exhibited a Significantly higher Specific capacitance of 1536 F g⁻¹ (CV at 1 mV s⁻¹) and 212.37 F g⁻¹ (GCD at 1 A g⁻¹) compared to sample-1, demonstrating that increasing lemon juice concentration enhances the capacitive behavior of V₂O₅ flakes by improving ion diffusion and electroactive surface area.\u0000</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13538-025-01896-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-Principles Study on Structural, Elastic, Mechanical, Electronic, Optical, and Thermoelastic Properties of Ge-Based Doped Halide Perovskites CsGeCl3-xBrx: Emerging Semiconductor Materials for Solar Cell and Photovoltaic Applications","authors":"M. Musa Saad H.-E.,&nbsp;B. O. Alsobhi,&nbsp;A. Almeshal","doi":"10.1007/s13538-025-01880-0","DOIUrl":"10.1007/s13538-025-01880-0","url":null,"abstract":"<div><p>In this paper, we present first-principles DFT calculations of the structural, elastic, mechanical, thermoelastic, optical, and electronic properties of mixed halide perovskites CsGeCl_3-xBr_x (x = 0, 1, 2, 3). CsGeCl_3-xBr_x crystallizes in a cubic (Pm-3m) structure at (x = 0, 3) and in a tetragonal (P4/mmm) when (x = 1, 2). CsGeCl_3-xBr_x are mechanically stable with intrinsic ductility and a Debye temperature <span>({theta }_{D})</span> above 97.4 ± 300 K. Using DFT with GGA-PBE and TB-mBJ functionals, we predict that semiconductor compounds CsGeCl_3-xBr_x are stable structures with direct band gap <span>({E}_{g})</span>, suitable for solar cells, photovoltaics, and related optoelectronic applications. The direct band gaps of CsGeCl_3-xBr_x are <span>({E}_{g})</span> = 1.105–1.431 eV (PBE) and <span>({E}_{g})</span> = 1.260–1.762 eV (mBJ). Also, the optical properties study reveals that the original peaks of CsGeCl_3-xBr_x materials lie in the visible light spectrum, confirming their candidate as a good absorber for solar cells. The results of this study confirm that through band gap tuning, we can obtain higher optical absorption ranges and greater efficiency for halide perovskite-based optoelectronics.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145037150","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":"Electronic Structures and Electrical and Magnetic Properties of Con (2 ≤ n ≤ 13) Clusters","authors":"G. A. Ceolin,&nbsp;G. R. C. Sampaio,&nbsp;C. T. Campos,&nbsp;F. E. Jorge","doi":"10.1007/s13538-025-01901-y","DOIUrl":"10.1007/s13538-025-01901-y","url":null,"abstract":"<div><p>Using the Douglas-Kroll-Hess level of theory, we calculated bond lengths, binding energies, vertical ionization potentials, HOMO-LUMO energy gaps, second-order differences of total energies, dissociation energies, and spin magnetic moments of small cobalt clusters with the B1B95 functional and the DZP+1<i>d</i>-DKH all-electron basis set. There is good agreement between our results and the experimental data found in the literature. The spin magnetic moments computed in this study are among the most accurate theoretical values published to date. These findings lend credibility to our predicted ground state geometric structures since they do not always coincide with previously found structures. Co₃ and Co₆ are the most stable clusters, while Co₁₁ is the most reactive. To help elucidate the electronic structures of cobalt clusters, we computed the static mean dipole polarizabilities and polarizability anisotropies for the first time in the literature.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145037146","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}