Pub Date : 2025-12-04DOI: 10.1016/j.ssc.2025.116275
Terufumi Yokota
The mean-field 10-state Potts glass model is studied focusing attention on the formation of metastable glassy states by rapid quenching Monte Carlo simulations. Metastable glassy state can be obtained by the rapid quenching in the model with a ferromagnetic interaction , in which the ferromagnetic state is the equilibrium ordered state. For a smaller value of , the system changes from a paramagnetic state to the ferromagnetic one and makes another change to a glassy state by annealing. For an even smaller value of , the glassy state changes to another glassy state at a lower temperature.
{"title":"Glassy states by rapid quenching in a mean-field Potts glass model","authors":"Terufumi Yokota","doi":"10.1016/j.ssc.2025.116275","DOIUrl":"10.1016/j.ssc.2025.116275","url":null,"abstract":"<div><div>The mean-field 10-state Potts glass model is studied focusing attention on the formation of metastable glassy states by rapid quenching Monte Carlo simulations. Metastable glassy state can be obtained by the rapid quenching in the model with a ferromagnetic interaction <span><math><msub><mrow><mi>J</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, in which the ferromagnetic state is the equilibrium ordered state. For a smaller value of <span><math><msub><mrow><mi>J</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, the system changes from a paramagnetic state to the ferromagnetic one and makes another change to a glassy state by annealing. For an even smaller value of <span><math><msub><mrow><mi>J</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, the glassy state changes to another glassy state at a lower temperature.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"409 ","pages":"Article 116275"},"PeriodicalIF":2.4,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692264","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 : 2025-11-28DOI: 10.1016/j.ssc.2025.116260
A.L. Samgin
Proton hopping in perovskite oxides is considered from an effective-mass viewpoint in the context of reported experimental studies of lattice vibrations that mediate the polaron formation. The charge carrier then appears as a Holstein-type small proton polaron, for which a certain lattice vibration oscillation then behaves as an assist phonon and promotes the proton to the adjacent oxygen host. Polaron mass behavior is investigated with a system plus reservoir model which extends our previous investigations (A.L. Samgin, Solid State Commun. 152 (2012) 585). The mass enhancement factor, which unlike the standard Larsen effective mass equation for the Holstein electron accounts explicitly for temperature dependent coupling effects, appears to be inherent to the phonon-assisted proton hopping regime. The proposed approach offers the possibility to describe certain aspects of the interaction of protons with phonons important for determining transport properties of oxides at both low- and high-temperatures.
在晶格振动介导极化子形成的实验研究中，从有效质量的角度考虑了钙钛矿氧化物中的质子跳跃。电荷载流子以荷尔斯坦型小质子极化子的形式出现，其一定的晶格振动振荡充当辅助声子，并将质子促进到邻近的氧宿主。用系统加储层模型研究极化子质量行为，该模型扩展了我们之前的研究（A.L. Samgin, Solid State common . 152(2012) 585）。质量增强因子与荷尔斯坦电子的标准拉森有效质量方程不同，它明确地说明了温度依赖的耦合效应，似乎是声子辅助质子跳跃机制所固有的。提出的方法提供了描述质子与声子相互作用的某些方面的可能性，这对于确定氧化物在低温和高温下的输运性质很重要。
{"title":"Temperature dependent proton-phonon coupling in perovskite oxides","authors":"A.L. Samgin","doi":"10.1016/j.ssc.2025.116260","DOIUrl":"10.1016/j.ssc.2025.116260","url":null,"abstract":"<div><div>Proton hopping in perovskite oxides is considered from an effective-mass viewpoint in the context of reported experimental studies of lattice vibrations that mediate the polaron formation. The charge carrier then appears as a Holstein-type small proton polaron, for which a certain lattice vibration oscillation then behaves as an assist phonon and promotes the proton to the adjacent oxygen host. Polaron mass behavior is investigated with a system plus reservoir model which extends our previous investigations (A.L. Samgin, Solid State Commun. 152 (2012) 585). The mass enhancement factor, which unlike the standard Larsen effective mass equation for the Holstein electron accounts explicitly for temperature dependent coupling effects, appears to be inherent to the phonon-assisted proton hopping regime. The proposed approach offers the possibility to describe certain aspects of the interaction of protons with phonons important for determining transport properties of oxides at both low- and high-temperatures.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"409 ","pages":"Article 116260"},"PeriodicalIF":2.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623188","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 : 2025-11-28DOI: 10.1016/j.ssc.2025.116265
A. Varaprasad , Rameeza Begum Sheik , Balakrishna Avula , Nageswara Rao Netinti , G. Chinna Ram , M. Gnana Kiran , Syed Inthiyaz , Malla Balakrishna , Anees A. Ansari
Here we reporting the structural, optical and magnetic properties changes occurred in orthoferrite of Yb1-xLaxFe1-xTixO3 (x = 0, 0.025 and 0.05) nanoparticles derived through sol-gel synthesis route, and tartaric acid used as a chelating agent. X-ray diffraction (XRD) analysis accompanied by Rietveld structure refinement established a single-phase of YbFeO3 (YbFO) orthorhombic crystal structure with Pnma space group. The X-ray photoelectron spectroscopy (XPS) studies revels that the concentration of oxygen vacancies was reduced from 24.12 to 20.32, with an increase of doping concentration from 0 to 5 mol% in YbFO matrix. The crystallite size was calculated using the Williamson-Hall (W-H) plots using XRD data and it was found to be decreasing crystallite size from 56 ± 5 nm to 36 ± 6 nm with an increase of doping and co-doping concentration from 0 to 5 mol% in YbFO matrix. An improved (∼1.5 time) magnetization value (saturation) was observed in 5 mol% doped and co-doped YbFO sample when compared to that of undoped YbFO sample, which indicates Fe3+–Fe3+ super-exchange interactions in the sample. Photocatalysis studies was also performed on these samples, and calculated rate constant for 5 mol% doped and co-doped YbFO nanomaterials was 0.0182 min−1 which is two times higher than that of pure YbFO nanomaterials (0.0089 min−1). These findings suggested that 5 mol% La doped and Ti co-doped nanomaterials could be a promising candidate for photocatalysis applications.
{"title":"Influence of La-Ti co-doping on structural, photocatalysis and magnetic performance of YbFeO3 nanoparticles derived from sol-gel method","authors":"A. Varaprasad , Rameeza Begum Sheik , Balakrishna Avula , Nageswara Rao Netinti , G. Chinna Ram , M. Gnana Kiran , Syed Inthiyaz , Malla Balakrishna , Anees A. Ansari","doi":"10.1016/j.ssc.2025.116265","DOIUrl":"10.1016/j.ssc.2025.116265","url":null,"abstract":"<div><div>Here we reporting the structural, optical and magnetic properties changes occurred in orthoferrite of Yb<sub>1-x</sub>La<sub>x</sub>Fe<sub>1-x</sub>Ti<sub>x</sub>O<sub>3</sub> (x = 0, 0.025 and 0.05) nanoparticles derived through sol-gel synthesis route, and tartaric acid used as a chelating agent. X-ray diffraction (XRD) analysis accompanied by Rietveld structure refinement established a single-phase of YbFeO<sub>3</sub> (YbFO) orthorhombic crystal structure with <em>Pnma</em> space group. The X-ray photoelectron spectroscopy (XPS) studies revels that the concentration of oxygen vacancies was reduced from 24.12 to 20.32, with an increase of doping concentration from 0 to 5 mol% in YbFO matrix. The crystallite size was calculated using the Williamson-Hall (W-H) plots using XRD data and it was found to be decreasing crystallite size from 56 ± 5 nm to 36 ± 6 nm with an increase of doping and co-doping concentration from 0 to 5 mol% in YbFO matrix. An improved (∼1.5 time) magnetization value (saturation) was observed in 5 mol% doped and co-doped YbFO sample when compared to that of undoped YbFO sample, which indicates Fe<sup>3+</sup>–Fe<sup>3+</sup> super-exchange interactions in the sample. Photocatalysis studies was also performed on these samples, and calculated rate constant for 5 mol% doped and co-doped YbFO nanomaterials was 0.0182 min<sup>−1</sup> which is two times higher than that of pure YbFO nanomaterials (0.0089 min<sup>−1</sup>). These findings suggested that 5 mol% La doped and Ti co-doped nanomaterials could be a promising candidate for photocatalysis applications.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"409 ","pages":"Article 116265"},"PeriodicalIF":2.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692262","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.2025.116264
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}
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