Applied Physics A最新文献_第9页

Morphology-dependent nonlinear optical response and single-wavelength all-optical or gate realization in Mn₃O₄ nanoparticles Mn₃O₄纳米颗粒的非线性光学响应和单波长全光或栅极实现

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10268-z

Jayaprasad K. V, Titu Thomas, Manu Vaishakh, Sheenu Thomas

{"title":"Morphology-dependent nonlinear optical response and single-wavelength all-optical or gate realization in Mn₃O₄ nanoparticles","authors":"Jayaprasad K. V, Titu Thomas, Manu Vaishakh, Sheenu Thomas","doi":"10.1007/s00339-026-10268-z","DOIUrl":"10.1007/s00339-026-10268-z","url":null,"abstract":"<div><p>The influence of nanoparticle morphology on the nonlinear optical response of Mn₃O₄ nanoparticles was systematically investigated using the spatial self-phase modulation (SSPM) technique with a 532 nm continuous-wave diode-pumped solid-state laser. Mn₃O₄ nanoparticles with three distinct morphologies were synthesized, and their nonlinear refractive indices were evaluated from the evolution of SSPM diffraction ring patterns. A pronounced dependence of the nonlinear refractive index on particle morphology was observed, demonstrating that morphological engineering provides an effective route for tailoring the nonlinear optical response of the material. The effect of optical path length on SSPM characteristics was also examined, revealing its significant influence on phase modulation and diffraction ring formation. In addition, efficient single-wavelength optical modulation was demonstrated through controlled SSPM, and an all-optical OR logic gate was successfully realized using the same excitation wavelength. The results establish morphology and propagation length as key parameters governing the nonlinear optical performance of Mn₃O₄ nanoparticles and highlight their potential for compact all-optical modulation, photonic logic, optical switching, and integrated nonlinear photonic devices.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Laser-fluence-driven structural evolution and colloidal stability of g-C₃N₄ nanoparticles prepared by pulsed laser ablation in liquid 脉冲激光烧蚀制备的g-C₃N₄纳米颗粒的激光驱动结构演化及胶体稳定性

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10266-1

Iman Abdul Salam, Adawiya J. Haider, Azhar I. Hassan, Ali J. Addie

{"title":"Laser-fluence-driven structural evolution and colloidal stability of g-C₃N₄ nanoparticles prepared by pulsed laser ablation in liquid","authors":"Iman Abdul Salam, Adawiya J. Haider, Azhar I. Hassan, Ali J. Addie","doi":"10.1007/s00339-026-10266-1","DOIUrl":"10.1007/s00339-026-10266-1","url":null,"abstract":"<div><p>Graphitic carbon nitride (g-C₃N₄) is an attractive metal-free polymeric semiconductor, but preserving its structural integrity during nanoparticle formation remains challenging. Here, g-C₃N₄ nanoparticles were synthesized by pulsed laser ablation in liquid (PLAL) in deionized water, and the effect of laser fluence on structure, morphology, composition, and colloidal behavior was systematically examined. Within 40–100 J cm⁻², laser fluence governed the balance between nanoscale fragmentation, structural disorder, and aggregation. The sample prepared at 40 J cm⁻² showed the clearest residual g-C₃N₄ diffraction and Raman signatures and the strongest electrostatic stabilization (ζ = −43.2 ± 3 mV). TEM-derived characteristic particle sizes decreased from approximately 114 to 80 and 46 nm with increasing fluence, indicating a morphological trend consistent with progressively stronger nanoscale fragmentation. In contrast, DLS showed increasing hydrodynamic aggregate size, accompanied by a reduction in zeta-potential magnitude at higher fluence. Increasing fluence also produced broader and less-defined XRD and Raman features together with increasingly irregular and aggregated morphologies. These findings establish a fluence-dependent process–structure–colloid relationship for PLAL-derived g-C₃N₄ and identify 40 J cm⁻² as the most favorable condition within the investigated range for balancing nanoparticle formation, structural retention, and electrostatic stabilization.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synergistic defect state modulation and charge carrier dynamics in cerium (Ce) doped Sb2Se3 thin films for visible-NIR photodetectors 可见光-近红外光电探测器中铈（Ce）掺杂Sb2Se3薄膜的协同缺陷态调制和载流子动力学

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10280-3

Muhammad Riaz, Muhammad Asif Shakoori, Syed Mansoor Ali, Ibrahim Aldawood, Kheir S. Albarkaty

{"title":"Synergistic defect state modulation and charge carrier dynamics in cerium (Ce) doped Sb2Se3 thin films for visible-NIR photodetectors","authors":"Muhammad Riaz, Muhammad Asif Shakoori, Syed Mansoor Ali, Ibrahim Aldawood, Kheir S. Albarkaty","doi":"10.1007/s00339-026-10280-3","DOIUrl":"10.1007/s00339-026-10280-3","url":null,"abstract":"<div><p>Defect-induced non-radiative recombination, carrier localization and inefficient charge transport kinetics are still major challenges that limit the performance of photodetectors. To address these limitations, Sb<sub>2</sub>Se<sub>3</sub> thin film doped with Ce (1% and 3%) was grown on glass substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) method. The structural, morphological, compositional, optical, electrical and photoresponse properties have been investigated by XRD, FE-SEM with EDX, XPS, UV-vis spectroscopy, PL spectroscopy, Hall-effect, I-V analysis, and transient photocurrent measurements. The successful incorporation of Ce into the host lattice is confirmed by XRD which shows the formation of well crystallized orthorhombic Sb<sub>2</sub>Se<sub>3</sub> phase. FE-SEM shows increment in grain size and microstructural compactness, whereas average grain size increases from ~ 146.5 to ~ 169.2 nm. The existence of Sb, Se, O, and Ce elements was also confirmed by XPS and EDX, indicating the chemical integrity of the films deposited. Additionally, Optical studies demonstrate enhanced photon absorption and bandgap modulation from 1.13 to 1.25 eV with Ce doping, while distinctive PL quenching indicates suppressed charge-carrier recombination and improved charge-separation efficiency. Concurrently, the charge-transport kinetics will be faster due to low resistivity and improved carrier mobility. Furthermore, photoelectrical measurements showed that the photocurrent increased from ~ 30 µA for the pristine film to ~ 145 µA for the 3% Ce-doped film, and transient photoresponse studies demonstrated excellent switching stability, reproducibility and operational reliability under periodic illumination. These synergistic findings highlight the significant potential of Ce-doped Sb<sub>2</sub>Se<sub>3</sub> thin films for advanced visible-NIR photodetector applications.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of cesium-based triple layer halide perovskites solar cell a high-performance photovoltaics 高性能光伏材料铯基三层卤化物钙钛矿太阳能电池的研究

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10260-7

Asad Ullah, Muhammad Faizan, Ohoud F. Al Sharif, Khamael M. Abualnaja, Khaled Fahmi Fawy

{"title":"Investigation of cesium-based triple layer halide perovskites solar cell a high-performance photovoltaics","authors":"Asad Ullah, Muhammad Faizan, Ohoud F. Al Sharif, Khamael M. Abualnaja, Khaled Fahmi Fawy","doi":"10.1007/s00339-026-10260-7","DOIUrl":"10.1007/s00339-026-10260-7","url":null,"abstract":"<div><p>The present study investigates the structural, optoelectronic and photovoltaic properties of cesium-based triple layer halide perovskites Cs₂SnBr₆, CsPbBr₃, and CsSnBr₃ using density functional theory (DFT) and SCAPS-1D simulation. The calculated electronic band gaps are 1.7 eV, 2.5 eV, and 1.3 eV for Cs₂SnBr₆, CsPbBr₃, and CsSnBr₃, respectively, and all three compounds exhibit direct band gaps. Their optical properties indicate robust absorption in the ultraviolet (UV) region, indicating their potential for optoelectronic applications. Subsequently, a novel triple-absorber-layer device architecture was proposed and numerically simulated. In this study, ten different device architectures were evaluated using SCAPS-1D by combining various electron transport layers (ETLs), namely WS₂, C60, LBSO, PCBM, and TiO₂ with hole transport layers (HTLs) including CBTS, CNTS, Cu₂Te, NiOₓ, and Spiro-OMeTAD. Among these, the architecture FTO/WS₂/CsSnBr₃/Cs₂SnBr₆/CsPbBr₃/CNTS/Au proved to be the most effective, yielding exceptional photovoltaic performance with a short-circuit current density (J<sub>SC</sub>) of 30.42 mA/cm², an open-circuit voltage (V<sub>OC</sub>) of 1.1543 V, a fill factor (FF) of 88.42%, resulting a power conversion efficiency (PCE) of 31.05%. Further analysis shows that the temperature rise leads to a decrease in the VOC and the PCE as a result of the higher reverse saturation current value and that the device efficiency can be significantly improved by increasing the shunt resistance value. This combined DFT and SCAPS-1D study gives important insights into the experimental work for the production of high-performance photovoltaic devices.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On-demand inverse design of terahertz polarization-converting metasurfaces via physics-constrained extreme learning machines 基于物理约束极限学习机的太赫兹偏振转换超表面的按需逆设计

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10256-3

Muhammed Malkoç, Burakhan Çubukçu

{"title":"On-demand inverse design of terahertz polarization-converting metasurfaces via physics-constrained extreme learning machines","authors":"Muhammed Malkoç, Burakhan Çubukçu","doi":"10.1007/s00339-026-10256-3","DOIUrl":"10.1007/s00339-026-10256-3","url":null,"abstract":"<div><p>Repeated inverse design of terahertz metasurfaces requires accurate, reusable predictions of complex scattering responses under physical constraints. We develop an angle-conditioned extreme learning machine (ELM) coupled with coordinate search for fixed-incidence geometry optimization. The ELM learns four complex scattering channels over 401 frequency samples from 7,776 CST-generated unit-cell configurations. Cross-channel equality is imposed by output parameterization, while radial spectral-norm scaling controls the adopted passivity bound. In the unseen incidence-angle test, mean MSE decreases from 0.0975 to 0.0169 relative to the data-driven ELM. Ablation identifies spectral scaling as the source of the accuracy gain; equality wiring supplies the structural constraint. With 2% and 5% labeled target-angle data, mean MSE is <span>(1.2783times 10^{-3})</span> and <span>(5.6210times 10^{-4})</span>, respectively. Independent full-wave validation on 50 off-grid targets gives mean complex MSEs of <span>(9.6272times 10^{-4})</span> for the proposed pipeline and <span>(9.5264times 10^{-4})</span> for the data-driven ELM plus genetic algorithm. Four new PCR-specific designs reuse the same trained model; three satisfy both polarization-conversion and reflected-power specifications at every prescribed band sample. The framework combines inexpensive repeated prediction and geometry search with reusable complex-response objectives and full-wave candidate verification.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microwave second-harmonic generation in compensated compound semiconductors at low lattice temperatures 低晶格温度下补偿化合物半导体微波二次谐波的产生

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10274-1

Bittu Roy, Souma Saha, Subhadipta Mukhopadhyay

{"title":"Microwave second-harmonic generation in compensated compound semiconductors at low lattice temperatures","authors":"Bittu Roy, Souma Saha, Subhadipta Mukhopadhyay","doi":"10.1007/s00339-026-10274-1","DOIUrl":"10.1007/s00339-026-10274-1","url":null,"abstract":"<div><p>The present study investigates microwave second-harmonic generation (SHG) in compensated III–V compound semiconductors at low lattice temperatures by considering non-degenerate electron ensembles interacting with deformation-potential acoustic phonons, piezoelectric phonons, and neutral and ionized impurities. A theoretical model based on non-equilibrium three-dimensional electron gas (3DEG) transport is employed to examine the dependence of SHG efficiency on the applied d.c. electric field in InSb, InAs, GaSb, and GaAs. The calculated SHG efficiency exhibits a strongly nonlinear dependence on the bias field, increasing initially, reaching a maximum at an optimum electric field, and subsequently decreasing at higher fields. A systematic comparative analysis reveals pronounced material-dependent behaviour arising from differences in electron mobility, effective mass, and carrier energy and momentum relaxation. GaAs exhibits the highest principal SHG efficiency at 1.35 K, but requires the highest optimum bias field among the four materials, whereas InAs and InSb achieve nearly comparable high efficiencies at relatively low optimum operating fields. GaSb exhibits lower SHG efficiency and requires a substantially higher electric field to attain its maximum response. Increasing the lattice temperature from 1.35 K to 4.2 K reduces the SHG efficiency in all four materials due to enhanced phonon scattering, with the magnitude of the temperature dependence varying among the materials. These results demonstrate that the interplay between carrier heating, non-ohmic transport, and competing scattering mechanisms governs microwave SHG efficiency and provides useful guidelines for the design of low-temperature nonlinear semiconductor devices.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Te substitution on optical and electrical characteristics of Te-Se-Ga-Ge chalcogenide glasses Te取代对Te- se - ga - ge硫系玻璃光学和电学特性的影响

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10259-0

Sukdeb Saha, Dipankar Biswas, Ajit Debnath

{"title":"Influence of Te substitution on optical and electrical characteristics of Te-Se-Ga-Ge chalcogenide glasses","authors":"Sukdeb Saha, Dipankar Biswas, Ajit Debnath","doi":"10.1007/s00339-026-10259-0","DOIUrl":"10.1007/s00339-026-10259-0","url":null,"abstract":"<div><p>In this research, an attempt is made to investigate the effect of the incorporation of Te on the structural, physical, optical, and electrical properties of TeₓSe<sub>(60−x)</sub>Ge₁₅Ga₂₅ quaternary chalcogenide glasses by employing the melt quenching technique. The glassy nature of all the glasses is verified by employing an X-ray diffraction technique. The introduction of Te in the glass network was seen to have a significant effect on the glass structure due to the larger atomic size and higher polarizability of Te compared to Se. This results in an increase in experimental density from 5.21 to 5.59 g/cm<sup>3</sup>, as well as an increase in molar and free volumes. From the optical studies, it is clear that there is a systematic change in the absorption edge towards the higher wavelength side with an increase in Te concentration in glasses, and there is an increase in Urbach energy and a decrease in optical band gap, showing more disorder in crystal structure. This is in agreement with the CBA model, where there is a decrease in cohesive energy with a decrease in bond strength due to replacement of Te-Se bonds by Se-Se bonds. The electrical measurements verify the thermal activation of electrical conduction. It is found that DC conductivity is enhanced with an increase in concentration of Te, while activation energy is reduced from 0.51 to 0.25 eV. Both the Mott and Greaves models of variable range hopping show an increase in localized states and a reduction in hopping distance. It is found that AC conductivity is in accordance with the universal power law of Jonscher, and data fit the correlated barrier hopping model with a reduction in barrier height from 1.04 to 0.65 eV. The scaling analysis confirms the universality of the electrical conduction process, irrespective of temperature and composition. The electrical conductivity and carrier mobility improve with Te substitution, making the glasses good candidates for optoelectronic and infrared optical devices.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanistic insight into temperature driven electro-optical optimization of spray deposited CdO thin films 温度驱动喷涂沉积CdO薄膜电光优化的机理研究

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10281-2

Mohamed El Fatah Nehal, karim salim, Ahmed Hichem Yahi, Walid Azzaoui, Abdelkader Nakrela

{"title":"Mechanistic insight into temperature driven electro-optical optimization of spray deposited CdO thin films","authors":"Mohamed El Fatah Nehal, karim salim, Ahmed Hichem Yahi, Walid Azzaoui, Abdelkader Nakrela","doi":"10.1007/s00339-026-10281-2","DOIUrl":"10.1007/s00339-026-10281-2","url":null,"abstract":"<div><p>Cadmium oxide (CdO) thin films were deposited on glass substrates by spray pyrolysis at substrate temperatures of 325, 350, and 375 °C to investigate the influence of thermal conditions on their structural, optical, and electrical properties. X-ray diffraction analysis confirmed the formation of polycrystalline CdO with a cubic structure and a preferential (200) orientation. The crystallinity, quantified from the relative integrated intensities of diffraction peaks and amorphous background, increased with temperature, reaching a maximum of 67.45% at 375 °C, indicating improved structural ordering. Optical measurements revealed an average transmittance ranging from 56% to 61% in the visible region, along with a slight widening of the direct optical band gap from 2.51 to 2.56 eV as the deposition temperature increased. The reduction in Urbach energy further evidenced a decrease in structural disorder. Hall effect measurements showed enhanced electrical performance, with decreasing resistivity and increasing carrier mobility at higher substrate temperatures. The film deposited at 375 °C exhibited the best balance between optical transparency and electrical conductivity, resulting in the highest figure of merit. These results demonstrate that substrate temperature plays a key role in optimizing the electro-optical performance of CdO thin films, highlighting their potential as efficient window layer materials for photovoltaic applications. </p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis and characterization of sol–gel synthesized NiCo2O4 nanoparticles for hybrid supercapacitor electrodes and devices 溶胶-凝胶合成纳米NiCo2O4复合超级电容器电极及器件的合成与表征

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-29 DOI: 10.1007/s00339-026-10270-5

Gourav Khajuria, Sandeep Arya

{"title":"Synthesis and characterization of sol–gel synthesized NiCo2O4 nanoparticles for hybrid supercapacitor electrodes and devices","authors":"Gourav Khajuria, Sandeep Arya","doi":"10.1007/s00339-026-10270-5","DOIUrl":"10.1007/s00339-026-10270-5","url":null,"abstract":"<div><p>In this study, nickel cobalt oxide (NiCo₂O₄) nanostructures were prepared using a sol–gel synthesis approach and investigated for their electrochemical energy storage performance. X-ray diffraction (XRD) pattern confirms the predominant formation of cubic spinel NiCo₂O₄, accompanied by weak reflections assigned to minor secondary phases, whereas SEM micrographs demonstrated a homogeneous nanoscale morphology that facilitates efficient ion diffusion and rapid electron transport during charge–discharge processes. FTIR spectra showed characteristic metal–oxygen vibrations, and XPS analysis verified the coexistence of Ni²⁺/Ni³⁺ and Co²⁺/Co³⁺ redox couples responsible for pseudocapacitive behaviour. Electrochemical evaluation in 6.0 M KOH demonstrated a high specific capacitance of 454.84 F g⁻¹ at 2 A g⁻¹ with good rate capability. A two-electrode supercapacitor assembled using NiCo<sub>2</sub>O<sub>4</sub> as the positive electrode and copper tape as the negative electrode delivered specific capacitance values of 202.66 to 5.83 F g⁻¹ over current densities of 2–10 A g⁻¹, along with 100% capacitance retention after 4500 cycles and Electrochemical impedance spectroscopy indicated a low equivalent series resistance of 1.6 Ω. A solid-state device was also successfully demonstrated, confirming the practical applicability of the electrode. Overall, the charge storage arises from Faradaic redox reactions at the NiCo<sub>2</sub>O<sub>4</sub>electrode combined with double-layer capacitance at the copper electrode, highlighting the suitability of sol–gel-derived NiCo<sub>2</sub>O<sub>4</sub> for efficient and stable supercapacitors.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microstructure and tribological behavior of a bilayer AlCoCrFeNi/Y₂O₃ high-entropy alloy coating fabricated via extremely high-speed laser cladding 超高速激光熔覆双层AlCoCrFeNi/Y₂O₃高熵合金涂层的微观结构和摩擦学行为

IF 3 4区材料科学

Applied Physics A Pub Date : 2026-09-28 DOI: 10.1007/s00339-026-10264-3

Hao Zhang, Mengying Qiao, Xiu-jie Yue, Ping Zhang, Xiangju Liu, Yuanxia Wang, Weiquan Sun, Xiaomei Ni, Yanan Zhang

{"title":"Microstructure and tribological behavior of a bilayer AlCoCrFeNi/Y₂O₃ high-entropy alloy coating fabricated via extremely high-speed laser cladding","authors":"Hao Zhang, Mengying Qiao, Xiu-jie Yue, Ping Zhang, Xiangju Liu, Yuanxia Wang, Weiquan Sun, Xiaomei Ni, Yanan Zhang","doi":"10.1007/s00339-026-10264-3","DOIUrl":"10.1007/s00339-026-10264-3","url":null,"abstract":"<div><p>In this study, single-layer (S₁) and double-layer (S₂) AlCoCrFeNi/Y₂O₃/ high-entropy alloy (HEA) coatings were fabricated on an aluminum alloy substrate using extreme high-speed laser cladding (EHLC). The effects of the double-layer structure on the microstructure and tribological properties of the coatings were investigated. The results indicate that the S₂ coating exhibits a smoother, denser surface morphology with significantly fewer defects, such as cracks and pores. X-ray diffraction (XRD) analysis reveals that the BCC phase content in the S₂ coating increases to 58.7 wt%. The average crystallite size increases to 22.02 nm, while both the dislocation density and microstrain are lower than those of the S₁ coating, indicating that the double-layer structure effectively optimizes the crystallinity and microstructural integrity of the coatings. Performance demonstrates that the microhardness of the S₂ coating reaches 1126.17 HV, representing an increase of approximately 54.5% compared to the S₁ coating. The average friction coefficient decreases to 0.362, and the wear rate is reduced to 3.93 × 10⁻⁵ mm³·N⁻¹·mm⁻¹. Furthermore, both the wear volume and wear scar length are lower than those of the S₁ coating. Analysis of the worn surfaces reveals a significant reduction in cracks on the S₂ coating, along with a more uniform distribution of the Y₂O₃ reinforcing phase, which effectively suppresses fatigue delamination and adhesive wear. The findings demonstrate that the double-layer structural design significantly enhances the comprehensive properties of the coatings by optimizing interlayer bonding and promoting the synergistic effect of strengthening mechanisms, endowing the S₂ coating with optimal tribological properties.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"132 10","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0