Pub Date : 2025-11-26DOI: 10.1016/j.ssc.2025.116264
Yury M. Basalaev , Ekaterina B. Duginova , Sofia A. Marinova
Using density functional theory (DFT) methods, we modeled the chalcopyrite crystal structure of five hypothetical LiMS2 crystals (M = B, Al, Ga, In, Tl). Equilibrium lattice parameters were determined, stability conditions were investigated, and elastic stiffness constants along with fundamental elastic moduli were calculated. Three-dimensional isosurfaces of Young's modulus and compressibility were constructed. Cauchy pressures, microhardness, Grüneisen parameter, Poisson's ratio, fracture toughness, and brittleness index were computed. Phonon and infrared (IR) spectra were obtained, and atomic contributions to vibrational modes of the studied crystals were analyzed. The comprehensive set of theoretical results indicates the feasibility of synthesizing and the stability of tetragonal LiMS2 crystals with the chalcopyrite lattice structure.
利用密度泛函理论（DFT）方法，模拟了五种假设的LiMS2晶体（M = B, Al, Ga, In, Tl）的黄铜矿晶体结构。确定了平衡晶格参数，研究了稳定条件，计算了弹性刚度常数和基本弹性模量。构造了杨氏模量和压缩率的三维等值面。计算了柯西压力、显微硬度、颗粒尼森参数、泊松比、断裂韧性和脆性指数。获得了声子和红外光谱，并分析了原子对所研究晶体振动模式的贡献。综合理论结果表明，合成具有黄铜矿晶格结构的四边形LiMS2晶体是可行的，且具有稳定性。
{"title":"First-principles study of properties of hypothetical chalcopyrite-structured disulfides","authors":"Yury M. Basalaev , Ekaterina B. Duginova , Sofia A. Marinova","doi":"10.1016/j.ssc.2025.116264","DOIUrl":"10.1016/j.ssc.2025.116264","url":null,"abstract":"<div><div>Using density functional theory (DFT) methods, we modeled the chalcopyrite crystal structure of five hypothetical Li<em>M</em>S<sub>2</sub> crystals (<em>M</em> = B, Al, Ga, In, Tl). Equilibrium lattice parameters were determined, stability conditions were investigated, and elastic stiffness constants along with fundamental elastic moduli were calculated. Three-dimensional isosurfaces of Young's modulus and compressibility were constructed. Cauchy pressures, microhardness, Grüneisen parameter, Poisson's ratio, fracture toughness, and brittleness index were computed. Phonon and infrared (IR) spectra were obtained, and atomic contributions to vibrational modes of the studied crystals were analyzed. The comprehensive set of theoretical results indicates the feasibility of synthesizing and the stability of tetragonal Li<em>M</em>S<sub>2</sub> crystals with the chalcopyrite lattice structure.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"409 ","pages":"Article 116264"},"PeriodicalIF":2.4,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623189","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}
Pub Date : 2025-11-26DOI: 10.1016/j.ssc.2025.116263
Maksymilian Kuna , Mateusz Raczyński , Julia Kucharek , Takashi Taniguchi , Kenji Watanabe , Tomasz Kazimierczuk , Wojciech Pacuski , Piotr Kossacki
We report an experimental study of the magnetic-field dependence of the optically pumped valley polarization in an epitaxial tungsten diselenide (WSe2) monolayer grown by molecular-beam epitaxy (MBE) on a hexagonal boron nitride (hBN) substrate. Circularly polarized photoluminescence (PL) measurements reveal that applying a weak out-of-plane magnetic field, on the order of 0.1 T, dramatically increases the effectiveness of the optical orientation of the emission associated with defect-bound localized excitons. We compare the obtained results with the earlier studies on the reference exfoliated monolayers, discussing both qualitative similarity as well as quantitative differences. Our observations are further supplemented by the results of time-resolved PL measurements, which confirm the pseudospin relaxation time of approximately 25 ps, a value significantly shorter than the 100 ps previously reported for mechanically exfoliated samples.
{"title":"Magnetic field induced polarization enhancement in the photoluminescence of MBE-grown WSe2 layers","authors":"Maksymilian Kuna , Mateusz Raczyński , Julia Kucharek , Takashi Taniguchi , Kenji Watanabe , Tomasz Kazimierczuk , Wojciech Pacuski , Piotr Kossacki","doi":"10.1016/j.ssc.2025.116263","DOIUrl":"10.1016/j.ssc.2025.116263","url":null,"abstract":"<div><div>We report an experimental study of the magnetic-field dependence of the optically pumped valley polarization in an epitaxial tungsten diselenide (WSe<sub>2</sub>) monolayer grown by molecular-beam epitaxy (MBE) on a hexagonal boron nitride (hBN) substrate. Circularly polarized photoluminescence (PL) measurements reveal that applying a weak out-of-plane magnetic field, on the order of 0.1 T, dramatically increases the effectiveness of the optical orientation of the emission associated with defect-bound localized excitons. We compare the obtained results with the earlier studies on the reference exfoliated monolayers, discussing both qualitative similarity as well as quantitative differences. Our observations are further supplemented by the results of time-resolved PL measurements, which confirm the pseudospin relaxation time of approximately 25 ps, a value significantly shorter than the <span><math><mo>≈</mo></math></span>100 ps previously reported for mechanically exfoliated samples.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"409 ","pages":"Article 116263"},"PeriodicalIF":2.4,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692263","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}
Pub Date : 2025-11-26DOI: 10.1016/j.ssc.2025.116262
Shaleni Venkatesan , B. Shunmugapriya , V. Balasubramanian
A novel, plant-based synthesis route utilizing Tabernaemontana divaricata leaf extract has been successfully employed for the synthesis of copper oxide (CuO) nanoparticles. This eco-friendly approach leverages the biomolecular reducing capabilities of the leaf extract, yielding a sustainable, cost-effective, and environmentally benign method for CuO nanoparticle production, with potential applications in energy storage, biomedical devices, and beyond. These green-synthesized CuO nanoparticles exhibited a monoclinic crystal structure with enhanced crystallinity, as confirmed by powder X-ray diffraction (XRD) analysis. Field-emission scanning electron microscopy (FE-SEM) revealed a distinct clustered morphology, differing from the typical petal/flake structures of conventionally synthesized CuO. Notably, vibrating sample magnetometry (VSM) measurements showed a significant increase in magnetization (Ms = ∼1.714 emu/g), exceeding previously reported values. This enhancement is attributed to the combined effects of nanoscale dimensions and surface modifications induced by the plant extract, which collectively contribute to the improved magnetic properties. These superior magnetic properties make the green-synthesized CuO nanoparticles promising candidates for a wide range of applications.
{"title":"Eco-friendly synthesis of CuO nanoparticles with Tabernaemontana divaricata leaf extract: Impact on structural and magnetic properties for biomedical applications","authors":"Shaleni Venkatesan , B. Shunmugapriya , V. Balasubramanian","doi":"10.1016/j.ssc.2025.116262","DOIUrl":"10.1016/j.ssc.2025.116262","url":null,"abstract":"<div><div>A novel, plant-based synthesis route utilizing Tabernaemontana divaricata leaf extract has been successfully employed for the synthesis of copper oxide (CuO) nanoparticles. This eco-friendly approach leverages the biomolecular reducing capabilities of the leaf extract, yielding a sustainable, cost-effective, and environmentally benign method for CuO nanoparticle production, with potential applications in energy storage, biomedical devices, and beyond. These green-synthesized CuO nanoparticles exhibited a monoclinic crystal structure with enhanced crystallinity, as confirmed by powder X-ray diffraction (XRD) analysis. Field-emission scanning electron microscopy (FE-SEM) revealed a distinct clustered morphology, differing from the typical petal/flake structures of conventionally synthesized CuO. Notably, vibrating sample magnetometry (VSM) measurements showed a significant increase in magnetization (<em>Ms</em> = ∼1.714 emu/g), exceeding previously reported values. This enhancement is attributed to the combined effects of nanoscale dimensions and surface modifications induced by the plant extract, which collectively contribute to the improved magnetic properties. These superior magnetic properties make the green-synthesized CuO nanoparticles promising candidates for a wide range of applications.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116262"},"PeriodicalIF":2.4,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621824","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}
Pub Date : 2025-11-24DOI: 10.1016/j.ssc.2025.116252
Yves Noat , Alain Mauger , William Sacks
In this article we show that the condensation mechanism in cuprates involves the strong coupling of the condensate to pairon excited states. We present an accessible formalism that significantly extends our previous work, providing a theoretical basis for the energy-dependent gap function . The latter is proportional to the effective spin exchange energy, , with no retardation effects, such as the case of spin-fluctuation or phonon mediated couplings. The fundamental parameters of the superconducting (SC) state are the condensation energy per pair, , and the antinodal energy gap, , which are quantitatively extracted by fitting the cuprate quasiparticle spectrum from tunneling experiments.
An explicit formula for the critical temperature is also derived in the model. Valid for any doping, we find to be proportional to , and not the gap , in sharp contrast to conventional SC. The numerical factor originates from pair excitations of the condensate, following Bose statistics, with a mini-gap meV in the excitation spectrum. These results strongly suggest that the same ‘all-electron’ mechanism is at work all along the -dome.
{"title":"Condensation mechanism of high-Tc cuprates: The key role of pairon excitations","authors":"Yves Noat , Alain Mauger , William Sacks","doi":"10.1016/j.ssc.2025.116252","DOIUrl":"10.1016/j.ssc.2025.116252","url":null,"abstract":"<div><div>In this article we show that the condensation mechanism in cuprates involves the strong coupling of the condensate to pairon excited states. We present an accessible formalism that significantly extends our previous work, providing a theoretical basis for the energy-dependent gap function <span><math><mrow><mi>Δ</mi><mrow><mo>(</mo><mi>E</mi><mo>)</mo></mrow></mrow></math></span>. The latter is proportional to the effective spin exchange energy, <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub></math></span>, with no retardation effects, such as the case of spin-fluctuation or phonon mediated couplings. The fundamental parameters of the superconducting (SC) state are the condensation energy per pair, <span><math><msub><mrow><mi>β</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>, and the antinodal energy gap, <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>, which are quantitatively extracted by fitting the cuprate quasiparticle spectrum from tunneling experiments.</div><div>An explicit formula for the critical temperature is also derived in the model. Valid for any doping, we find <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> to be proportional to <span><math><msub><mrow><mi>β</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>, and not the gap <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>, in sharp contrast to conventional SC. The numerical factor <span><math><mrow><msub><mrow><mi>β</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>/</mo><msub><mrow><mi>k</mi></mrow><mrow><mi>B</mi></mrow></msub><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>≃</mo><mn>2</mn><mo>.</mo><mn>24</mn></mrow></math></span> originates from pair excitations of the condensate, following Bose statistics, with a mini-gap <span><math><mrow><msub><mrow><mi>δ</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>≃</mo><mn>1</mn><mspace></mspace></mrow></math></span>meV in the excitation spectrum. These results strongly suggest that the same ‘all-electron’ mechanism is at work all along the <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>-dome.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116252"},"PeriodicalIF":2.4,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621823","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}
Pub Date : 2025-11-24DOI: 10.1016/j.ssc.2025.116261
Vusala Nabi Jafarova, Kh.O. Sadig, A.A. Hadiyeva, J.R. Sultanova
<div><div>The electronic and magnetic properties of silver-doped single-walled ZnO nanotubes (SW-ZnO:AgNTs) with (6,0) chirality were investigated using density functional theory (DFT). The structural model was constructed by substituting one Zn atom with an Ag atom in a (6,0) ZnO nanotube containing 12 Zn and 12 O atoms. For single substitution, one Zn atom was replaced by one Ag atom, corresponding to <em>x</em> ≈ 0.08 in Ag<sub><em>x</em></sub>Zn<sub>1-<em>x</em></sub>O. For double substitution, two Zn atoms were replaced by Ag atoms (<em>x</em> ≈ 0.16), placed at non-adjacent Zn sites to reduce artificial interaction. In the double substitution configuration, Ag atoms were positioned at a minimum distance of ∼6.38 <em>Å</em> to study the effect of non-interacting dopants on the electronic and magnetic properties. All structures were fully relaxed using a force convergence criterion of 0.01 eV/Å. Spin-polarized DFT calculations were performed for all configurations to capture the magnetic response induced by Ag doping. Our simulations, performed using the Quantum ATK software, reveal that Ag doping induces notable changes in the electronic structure, including a reduction of the band gap and the emergence of spin polarization.</div><div>For pristine SW-ZnONTs, we obtain a direct band gap of 3.10 eV, confirming their semiconducting and non-magnetic nature. Ag doping breaks this symmetry and introduces strong spin polarization. In the singly doped system, the spin-up channel retains a reduced band gap of about 2.5 eV, while the spin-down channel becomes almost gapless at the Fermi level, indicating clear half-metallic behavior. Double Ag doping preserves this asymmetry and further enhances spin polarization, with a slightly smaller spin-up band gap than in the singly doped case. Mulliken analysis reveals a total magnetic moment of approximately 1.0 <em>μ</em><sub><em>B</em></sub> for single doping, originating mainly from the oxygen atoms (∼0.8 <em>μ</em><sub><em>B</em></sub>) surrounding the Ag dopant and a smaller contribution from Ag itself (∼0.2 <em>μ</em><sub><em>B</em></sub>). Total energy calculations comparing ferromagnetic and antiferromagnetic configurations show that the FM phase is energetically more favorable by 0.048 eV, confirming the stability of ferromagnetism in the doped nanotube. Quantitative analysis of the bound magnetic polaron (BMP) characteristics reveals effective BMP radii of ∼2.2 <em>Å</em> and a significant increase in BMP number density from single to double Ag doping, confirming a percolative BMP-mediated mechanism that stabilizes long-range ferromagnetism above room temperature. The estimated Curie temperature (≈370 <em>K</em>) confirms that the singly Ag-doped SW-ZnONT maintains stable ferromagnetic ordering above room temperature, highlighting its potential for spintronic devices. The structural integrity is preserved post-doping, with minimal atomic distortion, low residual forces, and negligible stress values,
{"title":"Prediction of electronic and ferromagnetic characteristics OF ZnO:Ag nanotubes","authors":"Vusala Nabi Jafarova, Kh.O. Sadig, A.A. Hadiyeva, J.R. Sultanova","doi":"10.1016/j.ssc.2025.116261","DOIUrl":"10.1016/j.ssc.2025.116261","url":null,"abstract":"<div><div>The electronic and magnetic properties of silver-doped single-walled ZnO nanotubes (SW-ZnO:AgNTs) with (6,0) chirality were investigated using density functional theory (DFT). The structural model was constructed by substituting one Zn atom with an Ag atom in a (6,0) ZnO nanotube containing 12 Zn and 12 O atoms. For single substitution, one Zn atom was replaced by one Ag atom, corresponding to <em>x</em> ≈ 0.08 in Ag<sub><em>x</em></sub>Zn<sub>1-<em>x</em></sub>O. For double substitution, two Zn atoms were replaced by Ag atoms (<em>x</em> ≈ 0.16), placed at non-adjacent Zn sites to reduce artificial interaction. In the double substitution configuration, Ag atoms were positioned at a minimum distance of ∼6.38 <em>Å</em> to study the effect of non-interacting dopants on the electronic and magnetic properties. All structures were fully relaxed using a force convergence criterion of 0.01 eV/Å. Spin-polarized DFT calculations were performed for all configurations to capture the magnetic response induced by Ag doping. Our simulations, performed using the Quantum ATK software, reveal that Ag doping induces notable changes in the electronic structure, including a reduction of the band gap and the emergence of spin polarization.</div><div>For pristine SW-ZnONTs, we obtain a direct band gap of 3.10 eV, confirming their semiconducting and non-magnetic nature. Ag doping breaks this symmetry and introduces strong spin polarization. In the singly doped system, the spin-up channel retains a reduced band gap of about 2.5 eV, while the spin-down channel becomes almost gapless at the Fermi level, indicating clear half-metallic behavior. Double Ag doping preserves this asymmetry and further enhances spin polarization, with a slightly smaller spin-up band gap than in the singly doped case. Mulliken analysis reveals a total magnetic moment of approximately 1.0 <em>μ</em><sub><em>B</em></sub> for single doping, originating mainly from the oxygen atoms (∼0.8 <em>μ</em><sub><em>B</em></sub>) surrounding the Ag dopant and a smaller contribution from Ag itself (∼0.2 <em>μ</em><sub><em>B</em></sub>). Total energy calculations comparing ferromagnetic and antiferromagnetic configurations show that the FM phase is energetically more favorable by 0.048 eV, confirming the stability of ferromagnetism in the doped nanotube. Quantitative analysis of the bound magnetic polaron (BMP) characteristics reveals effective BMP radii of ∼2.2 <em>Å</em> and a significant increase in BMP number density from single to double Ag doping, confirming a percolative BMP-mediated mechanism that stabilizes long-range ferromagnetism above room temperature. The estimated Curie temperature (≈370 <em>K</em>) confirms that the singly Ag-doped SW-ZnONT maintains stable ferromagnetic ordering above room temperature, highlighting its potential for spintronic devices. The structural integrity is preserved post-doping, with minimal atomic distortion, low residual forces, and negligible stress values,","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116261"},"PeriodicalIF":2.4,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621822","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}
Pub Date : 2025-11-17DOI: 10.1016/j.ssc.2025.116243
Khan Karim , Rizwan Akram , Jan Sher Khan , Saima Rafique , Mozaffar Hussain , Muhammad Raza Hussain , Aon Muhammad , Zahid Qamar , Shehryar Zeeshan
Aluminum (Al) doped cadmium oxide CdO, x= (1 %, 3 %, 5 %, 7 %) was synthesized in the recent study via a composite hydroxide mediated (CHM) method. X-ray diffraction (XRD) confirmed the synthesis of pure CdO and the Al-doping in cubic cadmium oxide. The decrease in the lattice constant in Al-doped CdO confirmed the adequate substitution of Cd+2 by Al+3 ions in the CdO samples. Nanoscale particles and the morphology of the samples were examined through Field Emission Scanning Electron Microscopy (FESEM). Energy Dispersive Spectroscopy (EDX) was performed to verify the presence of Cd, O, and Al. Electrical conductivity, Seebeck coefficient, and thermal conductivity were recorded in the temperature range of 323–773 K. The electrical conductivity increased with increasing Al concentration, reaching an optimal value at x = 7 %. The n-type behavior was confirmed by the negative Seebeck coefficient of samples. The thermal conductivity was significantly reduced due to defects in the crystal lattice. The figure of merit, ZT measured from electrical conductivity, Seebeck coefficient and thermal conductivity data was observed to reach 0.221 for 7 % Al-doped CdO at 773 K. Consequently, in the present research, the thermoelectric figure of merit revealed a significant improvement of 63.70 % relative to the pure CdO at 773 K.
{"title":"Structural and thermoelectric properties of aluminum-doped CdO synthesized via Composite-hydroxide-mediated (CHM) approach","authors":"Khan Karim , Rizwan Akram , Jan Sher Khan , Saima Rafique , Mozaffar Hussain , Muhammad Raza Hussain , Aon Muhammad , Zahid Qamar , Shehryar Zeeshan","doi":"10.1016/j.ssc.2025.116243","DOIUrl":"10.1016/j.ssc.2025.116243","url":null,"abstract":"<div><div>Aluminum (Al) doped cadmium oxide CdO, x= (1 %, 3 %, 5 %, 7 %) was synthesized in the recent study via a composite hydroxide mediated (CHM) method. X-ray diffraction (XRD) confirmed the synthesis of pure CdO and the Al-doping in cubic cadmium oxide. The decrease in the lattice constant in Al-doped CdO confirmed the adequate substitution of Cd<sup>+2</sup> by Al<sup>+3</sup> ions in the CdO samples. Nanoscale particles and the morphology of the samples were examined through Field Emission Scanning Electron Microscopy (FESEM). Energy Dispersive Spectroscopy (EDX) was performed to verify the presence of Cd, O, and Al. Electrical conductivity, Seebeck coefficient, and thermal conductivity were recorded in the temperature range of 323–773 K. The electrical conductivity increased with increasing Al concentration, reaching an optimal value at x = 7 %. The n-type behavior was confirmed by the negative Seebeck coefficient of samples. The thermal conductivity was significantly reduced due to defects in the crystal lattice. The figure of merit, <em>ZT</em> measured from electrical conductivity, Seebeck coefficient and thermal conductivity data was observed to reach 0.221 for 7 % Al-doped CdO at 773 K. Consequently, in the present research, the thermoelectric figure of merit revealed a significant improvement of 63.70 % relative to the pure CdO at 773 K.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116243"},"PeriodicalIF":2.4,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578501","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}
Pub Date : 2025-11-16DOI: 10.1016/j.ssc.2025.116250
Emil I. Jaffal , Danila Shiryaev , Balaranjan Selvaratnam , Anton O. Oliynyk
We investigated the mechanical properties of Ta-rich regions of the Ta–P binary phase diagram, consisting of Ta and Ta3P (Ti3P-type) two-component samples, as well with inclusions of Fe to determine the effects on Vickers microhardness and on strength under compression loading. Different Ta concentrations in Ta3P produced diverse microstructural motifs, ranging from dispersed Ta dots (e.g., Ta81.3P18.7) and coagulated-like features (e.g., Ta84.4P15.6) to grouped lines and circular massed dot-line patterns (e.g., Ta85.9P14.1, Ta86.2P13.8) correlating with reduced load-bearing capacity and greater Vickers hardness. With increasing Ta concentration, microstructures evolved into contiguous leaf-like Ta phases (e.g., Ta90.4P9.6) and a homogenous intermediate without a pattern (e.g., Ta94.3P5.7), the latter exhibiting the highest compressive strength/total load (713 lbs) and lowest Vickers hardness (5.76 GPa at 0.5 kgf) of Ta–P compositions. Adjusting metal concentration (Ta alone or in tandem with Fe) produced similar quantitative correlations between hardness and compression strength. Electronic structure analysis using crystal orbital Hamiltonian population (COHP) revealed that Fe interstitial defects induce distinct modifications in p orbitals of phosphorus. The proposed chemical mechanism for strengthening, involving Fe–P orbital hybridization, namely between Fe d and P p states, was observed from −2 to −4 eV in density of states (DOS) calculation, corresponding to Fe–P bonding. This localized orbital overlap between Fe d and P p states produces peak splitting features resulting in a sharp peak at −4.5 eV. A secondary shoulder near −5.25 eV originates from downshifted P pz states. Orbital-resolved DOS analysis confirmed anisotropic participation of the p orbitals from P, highlighting defects driving localized bonding rearrangements.
{"title":"Investigating mechanical properties through defect chemistry in hard binary phosphide material Ta3P","authors":"Emil I. Jaffal , Danila Shiryaev , Balaranjan Selvaratnam , Anton O. Oliynyk","doi":"10.1016/j.ssc.2025.116250","DOIUrl":"10.1016/j.ssc.2025.116250","url":null,"abstract":"<div><div>We investigated the mechanical properties of Ta-rich regions of the Ta–P binary phase diagram, consisting of Ta and Ta<sub>3</sub>P (Ti<sub>3</sub>P-type) two-component samples, as well with inclusions of Fe to determine the effects on Vickers microhardness and on strength under compression loading. Different Ta concentrations in Ta<sub>3</sub>P produced diverse microstructural motifs, ranging from dispersed Ta dots (<em>e.g.</em>, Ta<sub>81.3</sub>P<sub>18.7</sub>) and coagulated-like features (<em>e.g.</em>, Ta<sub>84.4</sub>P<sub>15.6</sub>) to grouped lines and circular massed dot-line patterns (<em>e.g.</em>, Ta<sub>85.9</sub>P<sub>14.1</sub>, Ta<sub>86.2</sub>P<sub>13.8</sub>) correlating with reduced load-bearing capacity and greater Vickers hardness. With increasing Ta concentration, microstructures evolved into contiguous leaf-like Ta phases (<em>e.g.</em>, Ta<sub>90.4</sub>P<sub>9.6</sub>) and a homogenous intermediate without a pattern (<em>e.g.</em>, Ta<sub>94.3</sub>P<sub>5.7</sub>), the latter exhibiting the highest compressive strength/total load (713 lbs) and lowest Vickers hardness (5.76 GPa at 0.5 kgf) of Ta–P compositions. Adjusting metal concentration (Ta alone or in tandem with Fe) produced similar quantitative correlations between hardness and compression strength. Electronic structure analysis using crystal orbital Hamiltonian population (COHP) revealed that Fe interstitial defects induce distinct modifications in <em>p</em> orbitals of phosphorus. The proposed chemical mechanism for strengthening, involving Fe–P orbital hybridization, namely between Fe <em>d</em> and P <em>p</em> states, was observed from −2 to −4 eV in density of states (DOS) calculation, corresponding to Fe–P bonding. This localized orbital overlap between Fe <em>d</em> and P <em>p</em> states produces peak splitting features resulting in a sharp peak at −4.5 eV. A secondary shoulder near −5.25 eV originates from downshifted P <em>p</em><sub><em>z</em></sub> states. Orbital-resolved DOS analysis confirmed anisotropic participation of the <em>p</em> orbitals from P, highlighting defects driving localized bonding rearrangements.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116250"},"PeriodicalIF":2.4,"publicationDate":"2025-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578433","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}
Nd-doped BiFeO3 (Nd–BFO) nanoparticles were successfully synthesized via microwave-assisted combustion and sol–gel methods, and their structural, optical, and electrochemical properties were systematically investigated. X-ray diffraction confirmed the formation of a pure rhombohedral perovskite phase. UV–Vis spectroscopy revealed two distinct absorption edges, corresponding to charge transfer and crystal field transitions, respectively, with a direct band gap of 2.59 eV. Electrochemical studies performed in 3 M KOH electrolyte demonstrated typical pseudocapacitive behavior with enhanced redox activity for Nd-BFO. The Nd-BFO electrode exhibited a specific capacitance of 24 F/g at 2 A/g, with superior energy density (1.5 Wh/kg) and lower charge transfer resistance compared to undoped BFO. Moreover, the Nd–BFO electrode retained 80 % of its capacitance and maintained 85 % coulombic efficiency after 2000 cycles, highlighting its good electrochemical reversibility and stability. These results suggest that Nd doping effectively enhances the electrical conductivity, ion diffusion and electrochemical performance of BiFeO3, making Nd- BFO a promising electrode material for next-generation pseudocapacitor devices.
采用微波辅助燃烧和溶胶-凝胶法制备了nd掺杂BiFeO3纳米粒子，并对其结构、光学和电化学性能进行了系统研究。x射线衍射证实形成了纯菱形钙钛矿相。紫外可见光谱显示了两个明显的吸收边，分别对应于电荷转移和晶体场跃迁，直接带隙为2.59 eV。在3 M KOH电解液中进行的电化学研究表明，Nd-BFO具有典型的赝电容行为和增强的氧化还原活性。Nd-BFO电极在2 a /g时的比电容为24 F/g，与未掺杂的BFO相比，具有更高的能量密度（1.5 Wh/kg）和更低的电荷转移电阻。此外，经过2000次循环后，Nd-BFO电极保持了80%的电容和85%的库仑效率，突出了其良好的电化学可逆性和稳定性。这些结果表明，Nd掺杂有效地提高了BiFeO3的电导率、离子扩散和电化学性能，使Nd- BFO成为下一代伪电容器器件中有前景的电极材料。
{"title":"Effect of Nd doping on the structural and electrochemical behaviour of BiFeO3 nanoparticles","authors":"Uma Venkat , Abirami Selvakumar , Vijayalakshmi Pandurangan , Perumal Seenuvasakumaran , Vigneshwaran Baskaran","doi":"10.1016/j.ssc.2025.116251","DOIUrl":"10.1016/j.ssc.2025.116251","url":null,"abstract":"<div><div>Nd-doped BiFeO<sub>3</sub> (Nd–BFO) nanoparticles were successfully synthesized via microwave-assisted combustion and sol–gel methods, and their structural, optical, and electrochemical properties were systematically investigated. X-ray diffraction confirmed the formation of a pure rhombohedral perovskite phase. UV–Vis spectroscopy revealed two distinct absorption edges, corresponding to charge transfer and crystal field transitions, respectively, with a direct band gap of 2.59 eV. Electrochemical studies performed in 3 M KOH electrolyte demonstrated typical pseudocapacitive behavior with enhanced redox activity for Nd-BFO. The Nd-BFO electrode exhibited a specific capacitance of 24 F/g at 2 A/g, with superior energy density (1.5 Wh/kg) and lower charge transfer resistance compared to undoped BFO. Moreover, the Nd–BFO electrode retained 80 % of its capacitance and maintained 85 % coulombic efficiency after 2000 cycles, highlighting its good electrochemical reversibility and stability. These results suggest that Nd doping effectively enhances the electrical conductivity, ion diffusion and electrochemical performance of BiFeO<sub>3</sub>, making Nd- BFO a promising electrode material for next-generation pseudocapacitor devices.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116251"},"PeriodicalIF":2.4,"publicationDate":"2025-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145532760","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}
The study presents the tailored synthesis of WS2 nanosheets for energy storage applications. Several samples of WS2 nanosheets were synthesized by simple hydrothermal route at different pH levels of the precursor solution. The structural and morphological analysis was performed using characterization techniques including X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and electron microscopy. After performing the electrochemical measurements, an enhancement in the specific capacitance value of WS2- pH 5 sample was observed. The specific capacitance of WS2- pH 5 was found to be 167 F/g at a current density of 1 A/g which is about 5 times greater than the WS2-pH 7 nanosheets. This increase in the specific capacitance at pH 5 can be attributed to its smaller crystallite size and higher porosity. Thus, optimizing the synthesis conditions of WS2 nanosheets effectively improved energy storage capabilities.
该研究提出了用于储能应用的WS2纳米片的定制合成。在不同pH的前驱体溶液中，采用简单水热法合成了几种WS2纳米片样品。利用x射线衍射、拉曼光谱、x射线光电子能谱和电子显微镜等表征技术进行了结构和形态分析。在进行电化学测量后，观察到WS2- ph5样品的比电容值有所提高。在电流密度为1 a /g时，WS2- ph5的比电容为167 F/g，是WS2- ph7纳米片的5倍。pH值为5时比电容的增加可归因于其更小的晶粒尺寸和更高的孔隙率。因此，优化WS2纳米片的合成条件可以有效地提高其储能能力。
{"title":"Tuning hydrothermal conditions for superior electrochemical performance of WS2 nanosheets","authors":"Anjali Ghanghass , Ravi Bhatia , Mamta Bulla , Vinay Kumar","doi":"10.1016/j.ssc.2025.116248","DOIUrl":"10.1016/j.ssc.2025.116248","url":null,"abstract":"<div><div>The study presents the tailored synthesis of WS<sub>2</sub> nanosheets for energy storage applications. Several samples of WS<sub>2</sub> nanosheets were synthesized by simple hydrothermal route at different pH levels of the precursor solution. The structural and morphological analysis was performed using characterization techniques including X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and electron microscopy. After performing the electrochemical measurements, an enhancement in the specific capacitance value of WS<sub>2</sub>- pH 5 sample was observed. The specific capacitance of WS<sub>2</sub>- pH 5 was found to be 167 F/g at a current density of 1 A/g which is about 5 times greater than the WS<sub>2</sub>-pH 7 nanosheets. This increase in the specific capacitance at pH 5 can be attributed to its smaller crystallite size and higher porosity. Thus, optimizing the synthesis conditions of WS<sub>2</sub> nanosheets effectively improved energy storage capabilities.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116248"},"PeriodicalIF":2.4,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578503","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}
Pub Date : 2025-11-13DOI: 10.1016/j.ssc.2025.116242
Lin Zhang , Lijun Han , Zhen Cui
Two-dimensional materials play a critical role in advanced energy storage devices such as lithium-ion batteries. In this study, the potential of the MoS2/Nb2CO2 heterostructure as an LIB anode material was systematically investigated using density functional theory (DFT). The interlayer lithium-ion migration barrier is only 0.31 eV—about 46 % lower than that of typical MoS2-based heterostructures (e.g., MoS2/Ti2CO2, 0.57 eV)—indicating markedly improved ion transport capability. The average open-circuit voltage of 0.91 V is within the optimal range for anode materials and is favorable for suppressing lithium dendrite growth. The theoretical specific capacity reaches 412.4 mAh/g, representing a 1.76-fold increase over that of the Nb2CO2 monolayer. Moreover, the MoS2/Nb2CO2 heterostructure exhibits excellent thermal and cycling stability; even under full lithiation and elevated temperatures, it retains structural integrity with only minimal atomic vibrations. These systematic findings reveal that the MoS2/Nb2CO2 heterostructure successfully achieves effective synergy among high capacity, rapid ion migration, and structural stability, providing both new theoretical foundations and a promising candidate system for developing high-performance lithium-ion battery anode materials.
{"title":"MoS2/Nb2CO2 heterostructure as a two-dimensional anode material for lithium-ion batteries: A first-principles study","authors":"Lin Zhang , Lijun Han , Zhen Cui","doi":"10.1016/j.ssc.2025.116242","DOIUrl":"10.1016/j.ssc.2025.116242","url":null,"abstract":"<div><div>Two-dimensional materials play a critical role in advanced energy storage devices such as lithium-ion batteries. In this study, the potential of the MoS<sub>2</sub>/Nb<sub>2</sub>CO<sub>2</sub> heterostructure as an LIB anode material was systematically investigated using density functional theory (DFT). The interlayer lithium-ion migration barrier is only 0.31 eV—about 46 % lower than that of typical MoS<sub>2</sub>-based heterostructures (e.g., MoS<sub>2</sub>/Ti<sub>2</sub>CO<sub>2</sub>, 0.57 eV)—indicating markedly improved ion transport capability. The average open-circuit voltage of 0.91 V is within the optimal range for anode materials and is favorable for suppressing lithium dendrite growth. The theoretical specific capacity reaches 412.4 mAh/g, representing a 1.76-fold increase over that of the Nb<sub>2</sub>CO<sub>2</sub> monolayer. Moreover, the MoS<sub>2</sub>/Nb<sub>2</sub>CO<sub>2</sub> heterostructure exhibits excellent thermal and cycling stability; even under full lithiation and elevated temperatures, it retains structural integrity with only minimal atomic vibrations. These systematic findings reveal that the MoS<sub>2</sub>/Nb<sub>2</sub>CO<sub>2</sub> heterostructure successfully achieves effective synergy among high capacity, rapid ion migration, and structural stability, providing both new theoretical foundations and a promising candidate system for developing high-performance lithium-ion battery anode materials.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"408 ","pages":"Article 116242"},"PeriodicalIF":2.4,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621896","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号