The European Physical Journal B最新文献

{"title":"Synthesis, experimental and computational approach to optical, electronic and structural studies of N-acetyl l-alanine crystal","authors":"P. Krishnamoorthy,&nbsp;K. Premlatha,&nbsp;T. K. Arumugam,&nbsp;S. Seshadri,&nbsp;N. R. Rajagopalan","doi":"10.1140/epjb/s10051-025-00873-x","DOIUrl":"10.1140/epjb/s10051-025-00873-x","url":null,"abstract":"<div><p>Single-crystal <i>N</i>-acetyl-<span>l</span>-alanine (NALA), a semi-organic crystal, has been synthesized by slow evaporation growth technique in aqueous medium. An experimental study proves that it has the space group of P2₁2₁2 and orthorhombic crystal system. The unit-cell parameters of NALA crystal were identified using single-crystal XRD analysis. UV–vis analysis has been used to find out the cut-off wavelength of the crystal. The calculated Urbach energy and the related optical constant values support the non-linear optics (NLO) nature of NALA crystal. SEM and EDAX experiments were carried out to find the surface and elemental characteristics of the NALA crystal. Vickers micro-hardness studies have been utilized to probe the mechanical stability of the crystal. Kurtz–Perry Simple Harmonic Generation (SHG) study has suggested 1.4 times greater NLO efficiency of NALA crystal than that of standard KDP. Thermal stability of the crystal is demonstrated by TGA and DTA analysis. Glass transition (<i>T</i>_g) temperature is achieved through DSC analysis. Coats–Redfern method has been used to explain the thermodynamic parameters. The theoretical calculation done by density functional theory (DFT) and the computed values of polarizability calculations of NALA are compared and justifiable with the standard values. Polarizability and first-order hyperpolarizability (both static and dynamic) are calculated to see the potential application in non-linear optics and it is observed that the values are found to be 2.7 times greater than those of prototype at the same theoretical functional. The frontier study of HOMO–LUMO is used to interpret the global chemical molecular descriptors and indicate the applicability of the NALA crystal toward optical device fabrication.</p><h3>Graphical Abstract</h3><p>Hydrogen bonding graphical extract</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423443","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":"Photoacoustic dynamics in microtemperature semiconductor media with variable thermal conductivity and nonlocal effects","authors":"Tarek E. I. Nassar,&nbsp;A. M. S. Mahdy,&nbsp;Kh. Lotfy","doi":"10.1140/epjb/s10051-025-00877-7","DOIUrl":"10.1140/epjb/s10051-025-00877-7","url":null,"abstract":"<div><p>The study investigates the photoacoustic pressure effects on microtemperature distributions within a nanostructured (nonlocal) elastic semiconductor medium, where thermal conductivity is considered variable. Photoacoustic phenomena, which involve the generation of acoustic (elastic) waves due to the absorption of modulated light, play a pivotal role in heat transfer dynamics at the nanoscale. The interaction between photoacoustic pressure, plasma waves, and thermal waves influences localized temperature variations in semiconductor nanostructures. The variable thermal conductivity, which accounts for temperature dependence and nanoscale effects, adds complexity to the heat diffusion process. Using mathematical modeling and numerical simulations, the photoacoustic pressure-driven thermal response is analyzed in one dimension (1D) under different excitation frequencies and thermal conductivity profiles. Results show that the variable thermal conductivity significantly affects the propagation of thermal waves, acoustic pressure, elastic, mechanical, microtemperature, and carrier density diffusion, leading to enhanced heat confinement or dispersion depending on material properties and operating conditions. The findings have implications for the design of semiconductor devices where thermal management is critical, such as in photodetectors, microelectronic systems, and optoelectronic devices. This research advances the understanding of nanoscale heat transfer mechanisms in semiconductors under photoacoustic excitation and provides insight into optimizing thermal performance in nanostructured materials.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423398","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":"Subtle modulation of the nonlinear optical properties of GaAs quantum dot by the interplay between noise and impurity extension","authors":"Bhaskar Bhakti,&nbsp;Swarnab Datta,&nbsp;Anuja Ghosh,&nbsp;Manas Ghosh","doi":"10.1140/epjb/s10051-025-00880-y","DOIUrl":"10.1140/epjb/s10051-025-00880-y","url":null,"abstract":"<p>Current enquiry puts emphasis on unveiling the role of subtle interplay between <i>spatial dissemination of impurity</i> and <i>Gaussian white noise</i> on a few <i>nonlinear optical (NLO)</i> properties of the <i>doped GaAs quantum dot (QD)</i>. The NLO properties include <i>group index (GI)</i>, <i>DC-Kerr effect (DCKE)</i>, <i>electro-absorption coefficient (EAC)</i> and <i>optical gain (OG)</i>. GI, DCKE and EAC manifest red-shift with the enhancement of the spatial width of the dopant, both including and excluding noise. In case of OG, however, both with and without noise, the peak shift becomes non-uniform as the dopant stretch increases. The interplay between noise and the impurity spread becomes different for additive and multiplicative noise. Delicate modulation of impurity spread, in combination with the mode of introduction of noise, can control the regimes of fast and slow light in the system, the magnitudes of DCKE and EAC and can even cause maximization of OG and the current density in the vicinity of some typical spatial spread of the dopant.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143404113","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":"Influence of two-dimensional discrete breathers on the macroscopic properties of fcc metals","authors":"O. V. Bachurina,&nbsp;A. A. Kudreyko,&nbsp;D. V. Bachurin","doi":"10.1140/epjb/s10051-025-00875-9","DOIUrl":"10.1140/epjb/s10051-025-00875-9","url":null,"abstract":"<div><p>Delocalized nonlinear vibrational modes (DNVMs) in crystals are precise solutions to the equations governing atomic motion that are determined solely by the symmetry of the lattice. This study investigates the influence of two-dimensional discrete breathers (DBs) excited using four one-component DNVMs on the macroscopic properties of three-dimensional fcc single crystals of Al, Cu, and Ni. All results were obtained using molecular dynamics simulations. Key findings include the observation that the lifetime of two-dimensional DBs is significantly influenced by both the symmetry of the DNVM and the initial oscillation amplitude. The two-dimensional DBs exhibit hard-type nonlinearity, characterized by an increase in oscillation frequency with increasing initial amplitude. The excitation of the DBs leads to a reduction in the crystal's heat capacity, which becomes more pronounced with increasing amplitude. The presence of two-dimensional DBs induces thermal expansion within the crystal, suggesting an impact on the mechanical properties of the material. This research provides new insights into the role of DBs, in influencing the macroscopic properties of fcc metals.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423224","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":"Strain-modulation on electronic structures and magnetic properties of Fe doped monolayer 2H-MoS2: the first-principles calculation study","authors":"Wen-jing Lan,&nbsp;Hai-xin Li,&nbsp;Tong Du,&nbsp;Xue-ling Lin,&nbsp;Feng-chun Pan","doi":"10.1140/epjb/s10051-025-00872-y","DOIUrl":"10.1140/epjb/s10051-025-00872-y","url":null,"abstract":"<div><p>The first-principles calculation method is performed to explore the monolayer 2<i>H</i>-MoS₂:Fe semiconductors with intrinsic ferromagnetism and strong ferromagnetic coupling by strain-modulation. In this study, we demonstrate that the biaxial strain can effectively regulate the distribution of local magnetic moment, magnetic coupling ground state types and strength. The studied results indicate that one Fe_Mo dopant will bring 2 <span>(mu_{{text{B}}})</span> local magnetic moment, which is not affected by strains in range of − 6~6%. However, electronic configuration, occupation and magnetic moment distribution are closely related to strains. Moreover, smaller compressive strain can effectively strengthen ferromagnetic interactions between two Fe_Mo substitutions, and the most energy gains of ferromagnetic coupling reach to 153.9 meV under − 2% strain. However, the ferromagnetic ground state translates into antiferromagnetic one as strain in the range of − 6~ − 2.5%. The changes in magnetic moment and magnetic interaction originate from the competition between crystal-filed splitting and spin splitting under different strains. The theoretical results presented here predict that modulating the biaxial strain could be a very significant avenue to obtain intrinsic ferromagnetic 2<i>H</i>-MoS₂:Fe semiconductors.</p><h3>Graphical abstract</h3><p>The effect of strain on the electronic structures and magnetic properties of Fe doped monolayer 2<i>H</i>-MoS₂ were studied by first-principles calculations. We found that electronic configuration, occupancy and magnetic moment distribution are closely related to strains. Smaller compressive strain can effectively strengthen FM interactions between two Fe_Mo substitutions, and the most energy gains of FM coupling up to 153.9 meV under − 2% strain. However, the FM ground state translate into AFM one as strain in the range of − 6~− 2.5%. Our theoretical predictions highlight the important contribution of strain to electronic structures and magnetic properties, and present a valid avenue for the future design of high <i>T</i>_<i>C</i> material in monolayer MoS₂: Fe system.</p>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184809","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":"Publisher Correction: Language dynamics model with finite-range interactions influencing the diffusion of linguistic traits and human dispersal","authors":"Clément Zankoc,&nbsp;Els Heinsalu,&nbsp;Marco Patriarca","doi":"10.1140/epjb/s10051-025-00865-x","DOIUrl":"10.1140/epjb/s10051-025-00865-x","url":null,"abstract":"","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184810","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":"How oscillations in SIRS epidemic models are affected by the distribution of immunity times","authors":"Daniel Henrik Nevermann,&nbsp;Claudius Gros","doi":"10.1140/epjb/s10051-024-00858-2","DOIUrl":"10.1140/epjb/s10051-024-00858-2","url":null,"abstract":"<div><p>Models for resident infectious diseases, like the SIRS model, may settle into an endemic state with constant numbers of susceptible (<i>S</i>), infected (<i>I</i>) and recovered (<i>R</i>) individuals, where recovered individuals attain a temporary immunity to reinfection. For many infectious pathogens, infection dynamics may also show periodic outbreaks corresponding to a limit cycle in phase space. One way to reproduce oscillations in SIRS models is to include a non-exponential dwell-time distribution in the recovered state. Here, we study a SIRS model with a step-function-like kernel for the immunity time, mapping out the model’s full phase diagram. Using the kernel series framework, we are able to identify the onset of periodic outbreaks when successively broadening the step-width. We further investigate the shape of the outbreaks, finding that broader steps cause more sinusoidal oscillations while more uniform immunity time distributions are related to sharper outbreaks occurring after extended periods of low infection activity. Our main results concern recovery distributions characterized by a single dominant timescale. We also consider recovery distributions with two timescales, which may be observed when two or more distinct recovery processes co-exist. Surprisingly, two qualitatively different limit cycles are found to be stable in this case, with only one of the two limit cycles emerging via a standard supercritical Hopf bifurcation.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00858-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107943","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":"Inverse temperature dependent energy diffusion in positive and negative temperature regimes for the 1d coupled rotator lattice with bounded kinetic energy","authors":"Hongbin Chen,&nbsp;Nianbei Li","doi":"10.1140/epjb/s10051-025-00866-w","DOIUrl":"10.1140/epjb/s10051-025-00866-w","url":null,"abstract":"<p>The negative temperature with Boltzmann description can be realized in Hamiltonian with bounded energy terms such as the 1d coupled rotator lattice with bounded kinetic energy. Normal heat conduction behavior has also been found for this 1d nonlinear lattice model. In this paper, we will systematically investigate the energy diffusion behavior for such 1d nonlinear lattice in both the positive and negative temperature regimes via equilibrium diffusion method. Normal energy diffusion is confirmed with Gaussian fitting and inverse temperature dependent energy diffusion constants are obtained over the whole temperature range.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108238","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 annealing temperature on structural, optical and electrical properties of CdO nanoparticles for lighting applications","authors":"Jaswanth Arcot,&nbsp;Kaleemulla Shaik","doi":"10.1140/epjb/s10051-025-00867-9","DOIUrl":"10.1140/epjb/s10051-025-00867-9","url":null,"abstract":"<div><p>Cadmium oxide (CdO) nanoparticles (NP) were prepared using mechanical milling and annealing. The CdO powders were grinded for 16 h using Agate mortar and Pestle and subjected to air annealing at 400 °C, 500 °C, 600 °C and 700 °C for one hour. The powder samples annealed at different temperatures were subjected to various characterization techniques such as XRD, UV–Vis-NIR spectroscopy, FT-IR spectroscopy, Raman spectroscopy, photoluminescence spectrophotometer and electrical measurements. The XRD results confirmed the polycrystalline cubic structure of the CdO nanoparticles. Rietveld analysis from XRD revealed the structural formation of CdO nanoparticles. The crystallite size decreased from 33 to 24 nm with an increase in annealing temperature. The chemical bonds in FT-IR spectra confirmed the formation of CdO nanoparticles. Raman spectra of the CdO nanparticles were recorded at room temperature and observed two distinct peaks at 269 cm⁻¹ and 956 cm⁻¹. Optical absorbance and reflectance spectra were recorded using UV–Vis-NIR spectrophotometer and the optical band gap of the nanoparticles were calculated using Tauc’s relation and Cody’ method. A decrease in the band gap was observed in both methods. The PL spectra of the CdO nanoparticles were recorded at room temperature with an excitation wavelength of 380 nm and observed emission peaks at 423 nm, 485 nm, 532 nm, and 606 nm. The electrical resistivity of the CdO nanoparticles was studied using two-probe method using the Keithley source meter and observed decrease in resistivity with annealing temperature.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107989","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":"Thermodynamic parameters and phonon stability of CdX (X = Te, Se, S): a comparative study","authors":"Zalak S. Kachhia,&nbsp;Sunil H. Chaki,&nbsp;Sefali R. Patel,&nbsp;Jiten P. Tailor,&nbsp;Mitesh B. Solanki,&nbsp;Millind. P. Deshpande","doi":"10.1140/epjb/s10051-025-00870-0","DOIUrl":"10.1140/epjb/s10051-025-00870-0","url":null,"abstract":"<div><p>This study offers a comprehensive exploration of the thermal characteristics of cadmium chalcogenide (CdX, X = Te, Se, S) compounds. The CdXs are synthesized by mixing high purity precursor elements at elevated temperature under vacuum. The crystalline phases of the samples are investigated through X-ray diffraction (XRD) analysis. The XRD revealed that CdTe exhibits cubic, while CdSe and CdS possess a hexagonal crystalline phase. The thermal properties of CdTe, CdSe, and CdS compounds are determined from the acquired thermogravimetric (TG) and differential thermogravimetric (DTG) analysis. The TG and DTG curves are synchronously acquired for heating rate of 5 K·min⁻¹ in an inert nitrogen atmosphere, for temperature range of ambient to 1248 K. The results of TG analysis reveal that CdTe remains stable up to 965 K, whereas CdSe and CdS exhibit stability beyond 965 K upto 1125 K. The solitary peak in DTG analysis for each samples evident degradation of the samples in one step. The thermal degradation kinetics of all samples is assessed through the application of non-isoconversional Broido, Coats–Redfern, and Piloyan–Novikova relations. The findings from the kinetic parameters corroborate the observed trends in the thermocurves. The outcomes suggest that CdTe undergoes more pronounced weight loss with degradation initiated earlier than CdS and CdSe. The experimental findings about the thermal stability of CdX compounds are reinforced through theoretical investigation into phonon dynamics employing DFT simulations, offering requisite insights into their thermal behaviour.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107990","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}