Results in Physics最新文献

{"title":"Delocalized Ag−Ag dimer rattling mode contributes to reduced thermal conductivity and enhanced thermoelectric performance in AgAs2","authors":"Jie Zhang ,&nbsp;Minghao Zhan ,&nbsp;Wending Wang ,&nbsp;Xiaohong Xia ,&nbsp;Yun Gao ,&nbsp;Zhongbing Huang","doi":"10.1016/j.rinp.2025.108285","DOIUrl":"10.1016/j.rinp.2025.108285","url":null,"abstract":"<div><div>Layered thermoelectric materials inherently feature a decoupling of electron and phonon transport, attributed to the high electrical conductivity within the covalent atomic layers and the increased phonon scattering at the layer boundaries. However, the weak atomic interactions along the out-of-plane direction present a considerable obstacle in enhancing the thermoelectric performance of these materials. In this work, we employ RuAs₄ (FeAs₄), SrAs₄ (CaAs₄), and AgAs₂ (CuAs₂) as representative compounds to theoretically explore the influence of bonding characteristics on the carrier transport in quasi-layered structures. We find that, in comparison to RuAs₄ (FeAs₄) with a similar atomic mass and crystal structure, the room temperature lattice thermal conductivity can be dramatically decreased from 10.2 (5.6) W/mK to 0.83 (1.69) W/mK in SrAs₄ (CaAs₄). This reduction is linked to the weak ionic interaction between the covalently bonded As layers and the Sr (Ca) atoms, resembling a rattling model that effectively scatters heat-conducting acoustic phonons. Conversely, the subvalent Ag₂ dimers and delocalized Ag−As bonds in AgAs₂ ensure rational electrical transport while preserving significant lattice anharmonicity due to the dimer clusters’ rattler-like behavior. Coupled with an enhanced Seebeck coefficient resulting from the elevated valence band degeneracy, we predict an p-type average thermoelectric ZT of 2.8 at 400 K. Our results provide an approach for modulating carrier transport in layered thermoelectrics via atomic or cluster intercalation, potentially serving as a guide for identifying novel thermoelectric materials.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108285"},"PeriodicalIF":4.4,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Revisiting the effect of point defects on the decay of the longitudinal optical mode in semiconductors","authors":"Julian Anaya","doi":"10.1016/j.rinp.2025.108268","DOIUrl":"10.1016/j.rinp.2025.108268","url":null,"abstract":"<div><div>In a classic 2002 paper published by P.G. Klemens a theoretical analysis of the effect of point defects on the decay of the longitudinal optical mode in semiconductors was derived. The defect-induced phonon decay rate was analysed using convolution methods and second-order perturbation theory. In re-examining the derivation of these results, a critical error in the evaluation of an integral has been found, which is central to the main finding of the model. This letter demonstrates that the miscalculation leads to an incorrect scaling of the defect-induced broadening. In addition, a corrected derivation of the second-order perturbation result is given, yielding an amended expression for the optical phonon decay rate that aligns more closely with the expected physical behaviour. The revised result has significant implications for the quantitative interpretation of Raman line widths in isotopic mixtures and impurity systems, thereby refining the theoretical framework for analysing optical phonon decay in defective crystals.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108268"},"PeriodicalIF":4.4,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"International Advisory Board","authors":"","doi":"10.1016/S2211-3797(25)00167-6","DOIUrl":"10.1016/S2211-3797(25)00167-6","url":null,"abstract":"","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108273"},"PeriodicalIF":4.4,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Dynamics of quantum correlations in four-qubit XXZ Heisenberg model with external magnetic field","authors":"Su-Bok Ri,&nbsp;Gwang-Jin Kim,&nbsp;Ha Kim,&nbsp;Hyok Pak","doi":"10.1016/j.rinp.2025.108286","DOIUrl":"10.1016/j.rinp.2025.108286","url":null,"abstract":"<div><div>In this paper we argue about the quantum correlation (quantum entanglement and geometric quantum discord) in four-qubit XXZ Heisenberg Model. Here, the influence of uniform magnetic field on the dynamics of quantum correlation in cases of the antiferromagnetism has been mainly investigated. According to the results, it has been illustrated that the role of the uniform magnetic field on the dynamics of quantum correlation depends on the selection of the initial state. Furthermore, geometric quantum discord exhibits greater robustness compared to quantum entanglement. Also results show that the max values of quantum correlations decrease and the duration of quantum entanglement sudden death gets longer as purity parameter decreases, and that exchange interaction can substantially make an effect on the dynamics of the quantum correlation.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"74 ","pages":"Article 108286"},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Numerical investigation of thin film flow over a porous, non-flat moving sheet with nonlinear kinematics","authors":"Naeem Ullah ,&nbsp;Wang Jian ,&nbsp;Dil Nawaz Khan ,&nbsp;Sana Ben Moussa","doi":"10.1016/j.rinp.2025.108260","DOIUrl":"10.1016/j.rinp.2025.108260","url":null,"abstract":"<div><div>Flow of viscous thin film has previously been studied over a flat, porous and moving plate, whereas, these investigations are carried out for particular cases of uniform and linearly variable injection, suction, stretching and shrinking velocities. Moreover, the mechanisms of injection/suction and stretching/shrining have been analyzed individually and jointly for such flows. The present simulation has generalized the steady flow models of viscous thin film over porous, stretching and shrinking sheet of nonuniform thickness. We explored new and multiple dimensions of classical problems of thin film flow and analyzed it. Here, we categorically emphasized on the steady nature and kinds of injection (suction) and moving velocities of the sheet, whereas, steady form and variable size of the sheet are also taken into account. We formed different variables and investigated nonlinear cases of steady nature and checked different options for the two components of velocity, defined at the surface of sheet, variable sizes of the thin film and that of sheet. By analyzing all possible cases, we identified exact similarities that allowed the system of partial differential equations and boundary conditions to be precisely converted into ordinary differential equations based on these new variables. The transformed equation of continuity has two dimensionless parameters, which show that mass can be added/removed to/from the flow regime through two sources i.e. mass can be added/removed to/from the system by <strong>(i)</strong> injection/suction through porous sheet <strong>(ii)</strong> condensation/evaporation into/from the free surface. The system of exact ordinary differential equations is solved by <em><strong>bvp4c</strong></em> technique. Whereas, exact solutions of the system are also found under some restrictions on the parameters value. Besides that the two solutions are exactly matched to each other. Moreover, the present simulations are completely matched with the previously published work of this type for appropriate choices of functions and parameters. Note that the strict behavioral changes in the velocity profiles and skin friction coefficient are observed by changing the sign of parameters.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108260"},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Conduction mechanism investigation in YCa2Cu3Oδ colossal permittivity ceramics","authors":"Wael Chouk ,&nbsp;Mohamed Annabi ,&nbsp;Mouldi Zouaoui","doi":"10.1016/j.rinp.2025.108284","DOIUrl":"10.1016/j.rinp.2025.108284","url":null,"abstract":"<div><div>Sol-gel synthesized <span><math><mrow><mi>Y</mi><msub><mrow><mi>Ca</mi></mrow><mn>2</mn></msub><msub><mrow><mi>Cu</mi></mrow><mn>3</mn></msub><msub><mi>O</mi><mi>δ</mi></msub></mrow></math></span> ceramic exhibits giant permittivity <span><math><mrow><msubsup><mi>ε</mi><mrow><mi>r</mi></mrow><mo>′</mo></msubsup><mo>≈</mo><msup><mrow><mn>10</mn></mrow><mn>4</mn></msup></mrow></math></span>, low loss <span><math><mrow><mi>tan</mi><mi>δ</mi><mspace></mspace><mn>0.3</mn></mrow></math></span>, and high stability over frequency and temperature. XRD revealed a tetragonal phase (<em>P4/mmm</em>). XPS confirmed high oxygen vacancy density. The structural heterogeneity, shown by SEM, between neighboring grains results from Schottky barrier formation at the grain boundaries, potentially explaining the TCR phenomenon. Magnetic analysis showed paramagnetism. Electrical property investigation revealed an insulating-to-metallic phase transition with temperature, associated with changing conduction mechanisms. Paramagnetic-insulating behavior at higher temperatures is linked to thermal activation, while electron scattering contributes to paramagnetic-metallic conduction at lower temperatures. The resistivity behavior follows the percolation model, providing insights into the interplay between conducting and insulating phases, relevant for optimizing perovskite-based materials in electronics and energy storage.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108284"},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 role of calcination temperature on enhancing the dielectric and optical properties of CaCu3Ti4O11.8Cl0.2 material","authors":"Najwa Gouitaa ,&nbsp;Fatima Zahra Ahjyaje ,&nbsp;Taj-dine Lamcharfi ,&nbsp;Jamal Houssaini ,&nbsp;Mahjoub Daoudy ,&nbsp;Farid Abdi","doi":"10.1016/j.rinp.2025.108282","DOIUrl":"10.1016/j.rinp.2025.108282","url":null,"abstract":"<div><div>The role of calcination temperature on phase stability and dielectric properties improvement of CaCu₃Ti₄O_11.8Cl_0.2 was studied. Analysis using optical properties indicated a redshift of the absorption peaks, while the band gap energy was decreased up to 1.72 eV due to improved crystallinity and structural transformations taking place. A giant dielectric constant was reported of ε’_r = 4.1590 × 10⁴ with low dielectric losses of tanδ = 0.036 at 1 KHz for sample calcined at 900 °C/4h. The enhancement of dielectric properties was highly correlated with electrical behavior such as conductivity, activation energy (E_a), grain boundaries, and grain resistivity evolution. The findings were in accordance with the internal barrier layer capacitance (IBLC) model which considers grains and grain boundaries as critical contributors to the dielectric response. However, it is confirmed that the high value of grain boundary resistivity R_gb = 8.99 × 10⁶ Ω and low E_a = 0.28 eV are responsible for the low value of tanδ. While the low values of grain resistivity R_g = 111.67 Ω and grain growth contributed to the high ε’_r values. Moreover, the values of permittivity and losses reported in this study were compared to other halogen substitutions such as F^-, I^- and Br^- and showed better values, due to the electrical properties improvement, with the objective of making industrial capacitors and high-energy storage devices.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108282"},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Research and application of Gaussian coupled control bistable stochastic resonance system with independent parameter regulation","authors":"Tiantian Hou,&nbsp;Shangbin Jiao,&nbsp;Yi Wang,&nbsp;Nianlong Song,&nbsp;Jianghua Li,&nbsp;Wenchuan Cui","doi":"10.1016/j.rinp.2025.108283","DOIUrl":"10.1016/j.rinp.2025.108283","url":null,"abstract":"<div><div>The theory of Stochastic Resonance (SR) has drawn significant attention due to its exceptional ability to detect faint signals. Despite this, research to date indicates that for SR systems, whether they are monostable, bistable, or multi-stable, modifications to the system parameters lead to concurrent alterations in the depth and breadth of the potential wells when analyzing engineering signals, which results in suboptimal detection outcomes. To address these issues, a two-dimensional Gaussian bistable coupled SR (GBCSR) system has been proposed that can individually adjust the potential well characteristics. This innovative system facilitates the separate adjustment of shape characteristics of potential, allowing for more precise manipulation of the system’s dynamic response. The system’s non-linear dynamic traits are explicated through an analysis of the steady-state probability density (SPD) function and the mean first passage time (MFPT), substantiating the effectiveness of the new model. In practical scenarios, a variety of bearing defect signals serve as the objects of detection. The structural parameters of the GBCSR system are co-optimized using the Brain Storm Optimization (BSO) algorithm. This optimization approach leverages the algorithm’s ability to enhance population diversity and improve convergence accuracy, thereby optimizing the system’s performance. The experimental outcome results show that the proposed system can accurately detect the frequency of bearing fault signals. When compared with traditional SR systems such as the traditional bistable stochastic SR (TBSR), the traditional Gaussian SR system (TGSR), and the cascade stochastic resonance system, the proposed coupled system demonstrates superior performance.</div><div>This is achieved through the transfer of energy or information between subsystems, which enables more efficient utilization of noise energy. The system can trigger the resonance effect over a broader range of noise intensities and significantly enhance the signal-to-noise ratio (SNR) of weak signals under the same noise intensity.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108283"},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Optimizing hole transport materials and electrodes for enhanced performance in RbGeBr3-based on perovskite solar cells utilizing fullerene as an electron transport material","authors":"Shima Valizadeh ,&nbsp;Aliasghar Shokri ,&nbsp;Sani M. Lawal ,&nbsp;Nazila Fough","doi":"10.1016/j.rinp.2025.108280","DOIUrl":"10.1016/j.rinp.2025.108280","url":null,"abstract":"<div><div>In this work, the behavior of the electron transport material C60 and various organic and inorganic hole transfer materials, along with an inorganic perovskite material RbGeBr_3, has studied in different perovskite solar cells. The finite element method is utilized to compute solutions to the Poisson, continuity, and electrical transport equations. To obtain the highest efficiency among these cells, the thickness of the electron-transporting and light-absorbing layers has been changed. Additionally, how the various electron-collecting metal electrodes affect each structure’s optimum efficiency has been investigated. Among all these designed structures, the architecture FTO/C60/RbGeBr₃/NiO/Au has presented the highest efficiency of 16.48 %, along with an open circuit voltage of 0.92 V and a short circuit current of 22.25 mA/cm². Moreover, by changing the gold contact instead of the nickel contact, the efficiency obtained was approximately the same value. The results of this research could assist with creating improved and more efficient mineral perovskite-based solar cells.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108280"},"PeriodicalIF":4.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Neural network prediction of MHD thermo-solutal natural convection in ternary hybrid nanofluids within a curved enclosure","authors":"Saleh Mousa Alzahran ,&nbsp;Talal Ali Alzahrani ,&nbsp;Imtiaz Ali Shah","doi":"10.1016/j.rinp.2025.108275","DOIUrl":"10.1016/j.rinp.2025.108275","url":null,"abstract":"<div><div>In an era when optimizing energy efficiency and ensuring effective thermal management are essential, this study addresses the complex dynamics of MHD thermo-solutal natural convection (TSNC) within a curved cavity containing a unique ternary hybrid nanofluid (THNF) (Cu + CuO + Al₂O₃/H₂O). We explore the effects of key parameters, including Rayleigh number (Ra: 10⁴–10⁷), Hartman number (Ha: 0–100), volume fraction of nanoparticles (ϕ: 0–0.04), Lewis number (Le: 1–10), heat source length (H: 0.2–0.6), and heat source location (R: 0.25–0.75), on convective flow patterns, heat transfer, and mass movement. An artificial neural network (ANN) model is developed to investigate the influences of these parameters on the thermal and solute transport properties of THNF. The ANN model is trained using high-fidelity numerical simulation data to predict the thermosolutal convection behavior of THNF. This methodology accelerates predictive analysis but requires significant computational effort for training. Our precise representation of streamlines, isotherm lines and concentration profiles reveals that complex relationships between these variables. The results demonstrate that higher the <span><math><mrow><mi>Ra</mi></mrow></math></span> values improve heat and mass transfer, whereas increasing Ha suppresses convective motion due to electromagnetic damping from the Lorentz force. Increased <span><math><mi>ϕ</mi></math></span> enhances heat and mass tranfer, leading to stronger convection. <span><math><mrow><mi>Le</mi></mrow></math></span> analysis reveals that elevated values promote mass transfer over heat transfer. Although variation in heat source parameters affects flow structure and thermal gradient differently, the overall convective behavior depends on their interplay. Our comparison research show that the ternary hybrid nanofluid (<span><math><mrow><mi>Cu</mi><mo>+</mo><mi>C</mi><mi>u</mi><mi>O</mi><mo>+</mo><msub><mrow><mi>Al</mi></mrow><mn>2</mn></msub><msub><mi>O</mi><mn>3</mn></msub></mrow></math></span>) exhibits a higher average Nusselt number compared to the base fluid, the ternary hybrid nanofluid shows an increase in heat transfer efficiency of up to 78.33 % under specific conditions. These findings emphasize the potential of THNF and the modification of operational parameter, giving important insights for improving heat and mass transfer technologies across diverse industries.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"73 ","pages":"Article 108275"},"PeriodicalIF":4.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}