Younes Nezzari, Warda Darenfad, Kamel Mirouh, Noubeil Guermat, Nadir Bouarissa
{"title":"Structural, wettability, optical, and electrical modifications by varying precursor solutions of sprayed Co3O4 thin films for solar cell applications","authors":"Younes Nezzari, Warda Darenfad, Kamel Mirouh, Noubeil Guermat, Nadir Bouarissa","doi":"10.1140/epjb/s10051-025-00889-3","DOIUrl":"10.1140/epjb/s10051-025-00889-3","url":null,"abstract":"<p>Co<sub>3</sub>O<sub>4</sub> thin films were successfully deposited by spray pyrolysis with different precursor solutions, including cobalt nitrate, cobalt acetate, and cobalt chloride. The effect of these precursor solutions on the properties of the obtained Co<sub>3</sub>O<sub>4</sub> thin films was extensively studied. XRD analysis revealed that all three films exhibited polycrystalline nature with a preferred crystal orientation along the (311) plane. The crystallite size was observed to decrease for the films prepared using three different precursors: cobalt nitrate, cobalt chloride, and cobalt acetate, respectively. Raman spectroscopy provided further confirmation of the successful formation of the Co<sub>3</sub>O<sub>4</sub> spinel structure. AFM analysis demonstrated the significant impact of the cobalt source on surface morphology. The cobalt nitrate-based film exhibited a significantly lower surface roughness value of 15.29 nm, in contrast to the films prepared from cobalt chloride and cobalt acetate, which exhibited higher roughness values of 60.30 nm and 65 nm, respectively. Contact angle analysis revealed that all the samples exhibited a hydrophobic nature. UV–visible transmission spectra revealed that the film produced using cobalt nitrate has high light absorption and a smaller optical band gap. Electrical characterization further demonstrated that the Co<sub>3</sub>O<sub>4</sub> film prepared with cobalt nitrate had the lowest electrical resistivity (<i>ρ</i> = 2.905 × 10<sup>–1</sup> Ω.cm) among the films.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-00889-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581158","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}
L. Bruno Chandrasekar, A. Dinesh, Lalitha Gnanasekaran, Madhappan Santhamoorthy, M. Karunakaran, A. Manikandan, E. Priyadharshini, P. Shunmuga Sundaram, S. Kaleel Mohamed Ibrahim
{"title":"Spin-dependent resonant tunneling in CdTe/Cd1−xMnxTe nanostructures: effect of polaronic mass","authors":"L. Bruno Chandrasekar, A. Dinesh, Lalitha Gnanasekaran, Madhappan Santhamoorthy, M. Karunakaran, A. Manikandan, E. Priyadharshini, P. Shunmuga Sundaram, 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<sub>1−<i>x</i></sub>Mn<sub><i>x</i></sub>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":"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}
{"title":"Magnetic impurities in an altermagnetic metal","authors":"Yu-Li Lee","doi":"10.1140/epjb/s10051-025-00890-w","DOIUrl":"10.1140/epjb/s10051-025-00890-w","url":null,"abstract":"<p>We study the physics of dilute magnetic impurities in a two-dimensional altermagnetic metal. For the single impurity case, although the spin degeneracy is broken in an altermagnetic metal, we show that the antiferromagnetic Kondo coupling still flows to the strong coupling regime at low energies in terms of the one-loop renormalization-group equation. Moreover, the Kondo temperature may be enhanced or reduced, depending on whether or not the Fermi level is close to the Van Hove singularity at zero altermagnetic coupling. To study the ground-state properties, we employ the variational wavefunction approach. We find that the impurity spin is completely screened at long distances, in contrast to the usual antiferromagnet. The <i>d</i>-wave nature of the spin-split Fermi surfaces in an altermagnetic metal is reflected in the correlation between the impurity and conduction electron spins, which exhibits the <span>(C_{4z})</span> symmetry of the altermagnet at long distances. The spin correlation decays as <span>(1/r^3)</span> at long distances, and its amplitude oscillates with four different periods due to the interference between the spin splitting Fermi surfaces. Moreover, the values of these periods depend on the direction of observation. Similar phenomena also occur in the RKKY interaction in an AM metal.</p><p>The Fermi surface in an altermagnetic metal is split (left). Although a magnetic impurity in an altermagnetic metal is completely screened, the spin correlation between it and the conduction electrons exhibits nontrivial angular dependence (middle) ndue to the interference between spin-split Fermi surfaces. Similar behavior is also shown in the RKKY interaction (right).</p>","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":"143564418","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":"Orientation of active particles in gradient fields","authors":"Yuheng Zhong, Weirong Zhong","doi":"10.1140/epjb/s10051-025-00864-y","DOIUrl":"10.1140/epjb/s10051-025-00864-y","url":null,"abstract":"<div><p>We used non-equilibrium molecular dynamics simulations to investigate the effects of the orientation of dumbbell-shaped active particles. Self-driven dumbbell particles are situated between two particle reservoirs connected by a channel. By setting different environmental temperatures or particle concentrations in the two reservoirs, a non-equilibrium state with a temperature or concentration gradient is induced in the channel. It is found that the magnitude of the orientation of the active particles is directly proportional to the strength of the gradient field. The direction of the orientation is in line with the temperature gradient but opposite to the concentration gradient. Moreover, the orientation of active particles is also proportional to the self-propulsion force, while Brownian particles do not exhibit any orientation. The length of the dumbbell particle also has an impact on its orientation. When the spacing is zero, resulting in circular active particles, the orientational effect disappears. Additionally, we explored the potential limitations of traditional statistical mechanics methods in self-propelled particle systems. Our research contributes to a deeper understanding of the relationship between self-propulsion forces and the orientation of active particles.</p><h3>Graphical abstract</h3><p>Using non-equilibrium molecular dynamics, we have conducted a thorough investigation into the intricate relationships governing the orientation of active particles. Notably, the orientation aligns with the temperature gradient but opposes the concentration gradient, offering a unique insight into the behavior of these particles under varying conditions. Furthermore, we observed a positive correlation between the self-propulsion force of active molecules and their orientation. This correlation underscores the significance of self-propulsion in dictating the orientational behavior of these particles, which is absent in Brownian particles.</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":"143553731","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":"Probing the influence of hopping dimerization on persistent currents in cylindrical multi-channel systems","authors":"Ipshita Baruah, Anushka Patowary, Sudin Ganguly","doi":"10.1140/epjb/s10051-025-00892-8","DOIUrl":"10.1140/epjb/s10051-025-00892-8","url":null,"abstract":"<div><p>We explore the characteristics of persistent currents in cylindrical multi-channel systems influenced by a threaded magnetic flux. The cylindrical multi-channel system comprises vertically stacked one-dimensional (1D) rings, with each ring featuring hopping dimerization akin to the Su-Schrieffer-Heeger (SSH) model. Our description of the system is rooted in the nearest-neighbor tight-binding framework. Investigating the impact of the topological and trivial insulator scenarios inherent in the SSH model, we analyze their effects on both the energy spectrum and persistent current within this unique cylindrical multi-channel setup. Additionally, the influences of inter-ring coupling and cylinder size on the behavior of the persistent current are also analyzed.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554116","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":"Exploring the electronic, elastic anisotropy, and thermodynamic properties of Li2SiO3 and Li2GeO3 compounds using first-principles calculations","authors":"Jian-Li Ma, Zhi-Gang Fan, Qun Wei","doi":"10.1140/epjb/s10051-025-00886-6","DOIUrl":"10.1140/epjb/s10051-025-00886-6","url":null,"abstract":"<div><p>The first-principles calculation was employed to investigate the electronic structure, mechanical properties, and thermodynamic properties of Li<sub>2</sub>SiO<sub>3</sub> and Li<sub>2</sub>GeO<sub>3</sub> compounds. The optimized lattice parameters and atomic positions are in good agreement with the available experiment datas. The calculated formation enthalpy and elastic constant indicated that Li<sub>2</sub>SiO<sub>3</sub> and Li<sub>2</sub>GeO<sub>3</sub> compounds were thermodynamic and mechanical stability, respectively. The elastic properties, including bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio, were computed based on the obtained elastic constants. Furthermore, the elastic anisotropy was characterized by the graphs of three-dimensional (3D) surface constructions of elastic modulus. Finally, the longitudinal sound velocity, transverse sound velocity, Debye temperature, and minimum thermal conductivity were estimated by the elastic moduli. The obtained results can provide the relevant support of physical parameters for the development and application of Li<sub>2</sub>SiO<sub>3</sub> and Li<sub>2</sub>GeO<sub>3</sub> compounds.</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 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529947","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":"Speech perception: a model of word recognition","authors":"Jean-Marc Luck, Anita Mehta","doi":"10.1140/epjb/s10051-025-00882-w","DOIUrl":"10.1140/epjb/s10051-025-00882-w","url":null,"abstract":"<p>We present a model of speech perception which takes into account effects o correlations between sounds. Words in this model correspond to the attractors of a suitably chosen descent dynamics. The resulting lexicon is rich in short words, and much less so in longer ones, as befits a reasonable word length distribution. We separately examine the decryption of short and long words in the presence of mishearings. In the regime of short words, the algorithm either quickly retrieves a word, or proposes another valid word. In the regime of longer words, the behaviour is markedly different. While the successful decryption of words continues to be relatively fast, there is a finite probability of getting lost permanently, as the algorithm wanders round the landscape of suitable words without ever settling on one.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-00882-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496946","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}
Marcel Rodekamp, Evan Berkowitz, Christoph Gäntgen, Stefan Krieg, Thomas Luu, Johann Ostmeyer, Giovanni Pederiva
{"title":"Single-particle spectrum of doped (textrm{C}_{20}textrm{H}_{12})-perylene","authors":"Marcel Rodekamp, Evan Berkowitz, Christoph Gäntgen, Stefan Krieg, Thomas Luu, Johann Ostmeyer, Giovanni Pederiva","doi":"10.1140/epjb/s10051-024-00859-1","DOIUrl":"10.1140/epjb/s10051-024-00859-1","url":null,"abstract":"<p>We present a Hamiltonian Monte Carlo study of doped perylene <span>(textrm{C}_{20}textrm{H}_{12})</span> described with the Hubbard model. Doped perylene can be used for organic light-emitting diodes (OLEDs) or as acceptor material in organic solar cells. Therefore, central to this study is a scan over charge chemical potential. A variational basis of operators allows for the extraction of the single-particle spectrum through a mostly automatic fitting procedure. Finite chemical potential simulations suffer from a sign problem which we ameliorate through contour deformation. The on-site interaction is kept at <span>(nicefrac {U}{kappa }=2)</span>. Discretization effects are handled through a continuum limit extrapolation. Our first-principles calculation shows significant deviation from non-interacting results especially at large chemical potentials.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00859-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481214","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}
S. Rakhmanov, K. Matchonov, H. Yusupov, K. Nasriddinov, D. Matrasulov
{"title":"Optical high harmonic generation in Dirac materials","authors":"S. Rakhmanov, K. Matchonov, H. Yusupov, K. Nasriddinov, D. Matrasulov","doi":"10.1140/epjb/s10051-025-00885-7","DOIUrl":"10.1140/epjb/s10051-025-00885-7","url":null,"abstract":"<p>We study high-order harmonic generation by optically driven one- and two-dimensional hydrogen-like atoms formed by Coulomb impurities in graphene. The time-dependent Dirac equations with Coulomb plus time-periodic monochromatic field potentials are solved for both cases. Such characteristics of the optical high harmonic generation, as average dipole moment and high harmonic generation spectra, are computed. A sketch for table-top experimental realization of the considered models is proposed.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465965","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}