物理最新文献

{"title":"La and Cr induced structural modifications in BiFeO3 ceramics","authors":"Farha Jabeen,&nbsp;Aasim Hussain,&nbsp;Faisal Farooq,&nbsp;M. Shahid Khan,&nbsp;Raghvendra Pandey","doi":"10.1007/s00339-025-08334-z","DOIUrl":"10.1007/s00339-025-08334-z","url":null,"abstract":"<div><p>Bismuth ferrite (BiFeO₃) is a highly promising multiferroic material with extensive potential applications. This study investigates the impact of lanthanum (La) and chromium (Cr) doping on the structural properties of BiFeO₃ (BFO). Compositions BiFeO₃ (BFO), BiFe_0.95Cr_0.05O₃ (BFO1), Bi_0.95La_0.05Fe_0.95Cr_0.05O₃ (BFO2), and Bi_0.90La_0.10Fe_0.95Cr_0.05O₃ (BFO3) were synthesized using a solid-state reaction method at 800 ^oC. The incorporation of La and Cr into BFO aims to enhance its structural properties for potential applications in electronic and magnetic devices. Systematic analysis using X-ray diffraction (XRD), and Raman spectroscopy reveals significant changes in the lattice parameters, grain size, and phase stability of the doped ceramics. The rhombohedral structure of pure BFO, with the <i>R</i>3<i>c</i> space group, was confirmed as the primary phase through X-ray diffraction and Raman spectroscopy. The crystallite size obtained from both Scherrer’s and W-H method suggested that BFO1 sample has larger crystallite growth with low strain which favour the formation of dense and compact crystals. Rietveld refinement was done for BFO and BFO1 samples using FullProf suite to further analyses the crystal structure which also confirms the presence of <i>R</i>3<i>c</i> phase. The lattice constants increase for BFO1 and cell density decreases which infers the decrease in crystallinity for BFO1 sample. La doping results in an increase in the lattice parameters and an improvement in the crystallinity of the material, while Cr doping induces notable changes in the phase composition and microstructure. The combined effects of La and Cr doping lead to a more pronounced alteration in the structural characteristics, which are discussed in terms of the underlying mechanisms governing these modifications. These findings provide valuable insights into optimizing the synthesis and performance of BiFeO₃ ceramics for advanced technological applications.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generating and maintaining the high entangled photon pair and improving the strength of anti-correlation","authors":"M. Bohloul,&nbsp;A. Dehghani,&nbsp;H. Fakhri","doi":"10.1140/epjp/s13360-025-06010-y","DOIUrl":"10.1140/epjp/s13360-025-06010-y","url":null,"abstract":"<div><p>A theoretical scheme is proposed to generate a strongly entangled photon pair by a <span>(Lambda )</span>-configured three-level atom interacting with a two-mode quantized cavity field through two strong classical fields resonating with the corresponding atomic transitions. The initial state of the two-mode cavity field is considered to be the tensor product of an arbitrary Fock state of the first mode and the vacuum and one-photon states of the second mode, while that of the three-level atom is prepared in its upper excited state. Then, the time-evolution operator in the interaction picture is used to derive two classes of continuous variable entangled displaced number squeezed states (EDNSSs) in terms of the even and odd states of the second mode, respectively. The quadrature squeezing of the EDNSSs for the first mode in the initial vacuum state is considered concerning the coherent and squeezed fields. The sub-Poissonian statistics and the photon anti-bunching effect corresponding to both the coherent and squeezed fields are investigated in terms of the excited states of the first mode, as well as the coherent and squeezed fields with the same amplitudes. Furthermore, the cross-correlation between the two bosonic modes and their two-qubit entanglement are studied; and for example, it is shown that the destructive interference (anti-correlation) corresponds to an increase in entanglement. We highlight the role of the excited states of the first mode in controlling the nonclassical properties of the even and odd EDNSSs, compared to those of the entangled coherent-squeezed states (ECSSs).</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Sea-quark dynamics in decuplet ((frac{3}{2}^+)) (rightarrow ) octet ((frac{1}{2}^+)) transition quadrupole moment","authors":"Preeti Bhall,&nbsp;Alka Upadhyay","doi":"10.1140/epjc/s10052-025-13925-4","DOIUrl":"10.1140/epjc/s10052-025-13925-4","url":null,"abstract":"<div><p>We investigated the electromagnetic quadrupole transition of baryon decuplet (<span>(J^P= frac{3}{2}^+)</span>) to octet (<span>(J^P= frac{1}{2}^+)</span>) using the statistical framework together with the principle of detailed balance. The statistical approach assumed the expansion of hadrons in terms of various quark–gluon Fock states. By specifying the appropriate multiplicity in spin, color and flavor space, the relative probabilities of strange and non-strange quark–gluon Fock state are calculated. These probabilities further accumulated in the form of statistical parameters, highlighting the importance of sea quarks and gluons in the electromagnetic transition. Our calculations includes the individual contribution of valence and sea (scalar, vector and tensor ) to the transition moment of baryons. The effect of flavor SU(3) symmetry and its breaking in both valence and sea quarks is studied by incorporating the strange quark mass. The strangeness in the sea is constrained by a suppression factor <span>((1-C_l)^{n-1})</span>, which depends upon the free energy of gluons. The computed results get affected upto 60 <span>(%)</span> and exhibit the dominance of octet sea. The present work has been compared with updated experimental data and various theoretical predictions. The results obtained may offer important insights for future experimental studies.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 3","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-13925-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Tensile mechanical behavior of tungsten fiber network reinforced tungsten-copper composites: a numerical simulation study","authors":"Longchao Zhuo,&nbsp;Xiao Qi,&nbsp;Bin Luo,&nbsp;Nan Liu,&nbsp;Bingqing Chen,&nbsp;Jiacheng Sun,&nbsp;Hao Wang","doi":"10.1007/s00339-025-08359-4","DOIUrl":"10.1007/s00339-025-08359-4","url":null,"abstract":"<div><p>Tungsten fiber mesh reinforced copper-tungsten composites exhibit great application potential in aerospace and other fields due to their excellent mechanical properties. However, the influence of fiber mesh structural parameters on the mechanical behavior of the material remains unclear, necessitating systematic micromechanical research. In this study, an improved random sequential adsorption (RSA) algorithm is proposed to innovatively construct a refined three-dimensional random fiber mesh micromechanical model. Numerical simulations are systematically conducted to investigate the tensile mechanical properties of the material. The effects of microstructural parameters, such as fiber mesh diameter (40–200 μm), mesh number (30–100), rotation angle (0-90 °), and cross angle (15-90 °), on the tensile strength, plasticity, and anisotropy of the composite are explored. The regulatory mechanism of fiber mesh orientation and matrix deformation coordination on the mechanical behavior of the composite is elucidated, and the origin of material failure is revealed to be stress and strain concentration at fiber mesh nodes. The results show that with increasing fiber mesh diameter and mesh number, the tensile strength of the composite significantly improves, reaching 710 MPa at a fiber diameter of 200 μm and a mesh number of 100, representing an increase of 41% and 26% respectively compared to the baseline case. Fiber mesh rotation and crossing significantly affect the mechanical anisotropy of the material, with optimal material performance achieved when the angle between the loading direction and the fiber mesh is 0 °; while it is poorest at 45 °, with a difference of 34 MPa in tensile strength. This study establishes a computational simulation research paradigm for random fiber mesh composite material structural design, performance evaluation, and mechanism elucidation, providing important theoretical guidance for material optimization design. The research findings expand the analysis ideas and research methods for the mechanical behavior of composites and hold great significance for promoting the widespread application of fiber mesh composites in aerospace and other fields.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Parameterization of a Model for Wild Chickpea Flowering Time by Transferring Knowledge from Multiple Sources","authors":"Z. A. Saranin,&nbsp;M. G. Samsonova,&nbsp;K. N. Kozlov","doi":"10.1134/S0006350924700982","DOIUrl":"10.1134/S0006350924700982","url":null,"abstract":"<div><p>Forecasting flowering time allows researchers to create plant varieties that achieve maximum efficiency and value in the face of climate change. In this paper, we propose an algorithm for parameterizing the flowering time model of wild chickpea samples, which uses the transfer learning technique to combine several sets of source data and target data. The constructed model, using genetic and climatic data only for the first 20 days after sowing, predicts the flowering time of the samples with high accuracy; the average absolute error is slightly more than 5 days and the Pearson correlation coefficient is 0.93. It was found that the maximum and minimum temperatures have the strongest effect on the flowering time. At the same time, all weather factors on the seventh–tenth day after sowing influence the solution of the model.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 5","pages":"892 - 898"},"PeriodicalIF":4.033,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanisms of the Formation and Function of Dinitrosyl Iron Complexes as a “Working Form” of Nitric Oxide in Living Organisms","authors":"A. F. Vanin","doi":"10.1134/S000635092470101X","DOIUrl":"10.1134/S000635092470101X","url":null,"abstract":"<div><p>The thesis is proposed that only the inclusion of endogenous nitric oxide (NO) in living organisms in dinitrosyl iron complexes or in S-nitrosothiols can provide its stabilization, which is necessary for the functioning of NO as both an auto- and paracrine regulator of metabolic processes. Without such inclusion, the nearly all the endogenous NO disappears due to the aggressive action of the intracellular and extracellular medium of the body on it and is thereby excluded from processes of vital activity. The introduction of exogenous NO into the body of animals and humans (possible only by inhalation of its gaseous form) does not lead to the formation of either dinitrosyl iron complexes or S-nitrosothiols in blood and other tissues. In this case, the nearly all the exogenous NO is converted in the blood into nitrosonium (NO⁺) cations, the appearance of which is evidenced by their conversion into S-nitrosothiols under simultaneous inhalation of exogenous NO with the introduction of various thiols into the blood of animals. As well, the appearance of S-nitrosothiols in these animals is detected by their hypotensive effect on animals. The conversion of NO into nitrosonium cations also occurs during the synthesis of dinitrosyl iron complexes, as caused in living organisms by the reaction of disproportionation of endogenous NO molecules that bind in pairs with ferrous ions. The subsequent binding of Fe(NO)₂ groups arising during this reaction with thiol-containing ligands leads to the formation of sufficiently stable dinitrosyl iron complexes that function in living organisms as donors of both neutral NO molecules and nitrosonium (NO⁺) cations. The transfer of the latter to the targets of their biological effects is carried out as a result of direct contact of low-molecular-weight dinitrosyl iron complexes, respectively, with the heme group of heme-containing proteins (for example, guanylate cyclase) or with thiol groups of low molecular weight and protein thiol-containing compounds. Various consequences of such NO and NO⁺ transfer in living organisms are presented, which are both positive, regulatory, and negative, toxic.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 5","pages":"937 - 954"},"PeriodicalIF":4.033,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of the Diffusion of an Electroactive Molecule in Biosimilar Hydrogel Media","authors":"I. A. Cherenkov,&nbsp;M. D. Krivilyov,&nbsp;M. M. Ignat’eva,&nbsp;A. Yu. Emel’yanova,&nbsp;V. G. Sergeev","doi":"10.1134/S0006350924700891","DOIUrl":"10.1134/S0006350924700891","url":null,"abstract":"<div><p>Based on the experimental data of cyclic voltammetry, the diffusion coefficients of toluidine blue in alginate and gelatin hydrogels, as well as in their combinations, were determined. Using the experimental coefficients in the digital model, calculations of the reduction currents were carried out, which showed compliance with the experimental results. It is proposed to use the time when the current reaches a stationary level as an indicator of the diffusion properties of a hydrogel medium. The results are to be used to develop methods for evaluating the diffusion properties of hydrogel media, that is, bioinks and tissue engineering structures.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"69 5","pages":"811 - 819"},"PeriodicalIF":4.033,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin-dependent resonant tunneling in CdTe/Cd1−xMnxTe nanostructures: effect of polaronic mass","authors":"L. Bruno Chandrasekar,&nbsp;A. Dinesh,&nbsp;Lalitha Gnanasekaran,&nbsp;Madhappan Santhamoorthy,&nbsp;M. Karunakaran,&nbsp;A. Manikandan,&nbsp;E. Priyadharshini,&nbsp;P. Shunmuga Sundaram,&nbsp;S. Kaleel Mohamed Ibrahim","doi":"10.1140/epjb/s10051-025-00888-4","DOIUrl":"10.1140/epjb/s10051-025-00888-4","url":null,"abstract":"<div><p>Effect of polaronic mass on the resonant tunneling of electrons in CdTe/Cd_1−<i>x</i>Mn_<i>x</i>Te double-barrier heterostructure is investigated. The well-known transfer matrix method is employed to calculate the barrier transparency. One can obtain a high degree of spin-polarization at a high concentration of Mn in the barrier region. The barrier transparency peak becomes narrow as the concentration of Mn increases from 10 to 20%. The effect of polaronic mass shifts the transparency peak to the lower value on the energy scale. One can obtain a high degree of spin-polarization at a high concentration of Mn in the barrier region. The account of the polaronic mass shifts the resonance energy of spin-polarization to the lower value and it enhances the spin-polarization. The spin-down electrons spend more time in the heterostructure than the spin-up electrons. The dwell time changes about 1000 times as the concentration of the barrier changes.</p><h3>Graphical abstract</h3><p>Spin separation versus Mn concentration (a) without the account of polaronic mass and (b) with the account of polaronic mass</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 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553732","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":"Tunability of a microchip Yb:KGW solid-state laser self-injected with different wavelength-selective external cavities","authors":"Haroldo Maestre,&nbsp;Miguel Cuenca,&nbsp;Angela E. Ortega","doi":"10.1007/s00340-025-08426-x","DOIUrl":"10.1007/s00340-025-08426-x","url":null,"abstract":"<div><p>This work investigates tunable emission in a continuous-wave Yb:KGW microchip-type solid-state laser utilizing an external cavity. While microchip lasers offer advantages like compactness and simplicity, achieving broad tunability within the compact laser structure presents challenges. The influence of crystal position relative to the pump on the emission polarization was explored. To achieve pump-independent tuning, two external cavity configurations were implemented, including a Littrow configuration with a diffraction grating and a configuration employing a bandpass filter. The filter-based configuration demonstrated superior performance, enabling a tuning range exceeding 35 nm. The obtained results demonstrate the potential of external cavity techniques to enhance the tunability and performance of microchip lasers for applications requiring wavelength-agile sources.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00340-025-08426-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Density functional theory study on structural, mechanical, electronic, and phonon properties of CrAlB, MoAlB, WAlB, CrAlGa, MoAlGa, and WAlGa ternary compounds","authors":"B. O. Mnisi","doi":"10.1140/epjb/s10051-025-00876-8","DOIUrl":"10.1140/epjb/s10051-025-00876-8","url":null,"abstract":"<div><p>In this study, we present the structural, mechanical, electronic, and optical properties of CrAlB, MoAlB, WAlB, CrAlGa, MoAlGa, and WAlGa compounds using first-principles density functional theory calculations. We assessed structural stability through heat of formation and found that most compounds have negative heat of formation indicating thermodynamic stability, except for MoAlGa and WAlGa. The elastic constants and moduli indicate that all CrAlB, MoAlB, WAlB, CrAlGa, MoAlGa, and WAlGa compounds are mechanically stable, exhibit elastic anisotropic behavior, relatively machinable, and mixed bonding characteristics with both ionic and covalent contributions. The MAlB (M = Cr, Mo, W) compounds display a brittle nature, whereas MAlGa exhibits ductile behavior. Analysis of Vickers hardness indicate that MAlB compounds are hard compared to MAlGa. The electronic band structures and density (DOS) of states indicate a clear metallic nature in both MAlGa and MAlB compounds. The electronic density difference plots indicate a spherical charge distribution with ionic bonding in MAlB and oblate charge distribution showing covalent bonding in MAlGa. Phonon dispersion analysis demonstrated dynamic stability in MAlB compounds, while MAlGa are dynamically unstable. We note that MAlB compounds are thermodynamically, mechanically, and dynamically stable, making them suitable for high-temperature structural applications such as aerospace and gas turbine engines.</p><h3>Graphical abstract</h3><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 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-00876-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564419","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}