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Exploring the structural and optical properties of Zn1-x-yCuxReyO compound obtained by solid-state reaction

Ceramics International 2025年第13期51卷 18212-18225页

作者： Castro-Lopes, S. Pereira, Juliane P. Guerra, Y. Trigueiro, Pollyana Garcia-Fornaris, I. Govea-Alcaide, E. Hernández, E. Padrón- Peña-Garcia, Ramón R. Federal Institute of Education Science and Technology of Pará Altamira PA Brazil Federal Rural University of Pernambuco Postgraduate Program in Physics Engineering Academic Unit of Cabo de Santo Agostinho Cabo de Santo Agostinho PE Brazil Institute of Physics Federal University of Alagoas AL Maceió57072-900 Brazil Federal University of Pernambuco Department of Physics PE Recife Brazil Federal University of Maranhão Department of Physics MA São Luis Brazil

This study investigates the structural and optical properties of the Zn1-x-yCuxReyO compound synthesized via solid-state reaction as a promising material for optoelectronic applications. The Cu2+ and Re4+ doping led to changes in the lattice parameters (reduction of a from 3.2432 Å to 3.2373 Å and c from 5.1947 Å to 5.1869 Å), average crystallite size (D, varying from 121 nm to 89 nm), and dislocation density (δ, ranging from 0.69 × 10−4 nm−2 to 1.27 × 10−4 nm−2). The Raman analysis indicated shifts in the E2low (98.08 cm−1 to 99.04 cm−1), and E2high (436.83 cm−1 to 437.68 cm−1) modes, suggesting reduced lattice parameters and increased defect concentration, particularly oxygen vacancies (Vo). Micrography analysis revealed that dopant concentration increased the particle cluster size and uniformity. The energy band gap (Eg) decreased from 3.183 ± 0.002 eV for the ZCR00 sample to 2.828 ± 0.002 eV, 2.868 ± 0.002 eV, and 2.857 ± 0.001 eV for the ZCR31, ZCR33, and ZCR35 samples, respectively, indicating the formation of new energy states. Refractive index values calculated using Moss, Herve-Vandamme, and Kumar-Singh models, ranged from 2.33 eV to 2.40 eV, consistent with band gap values. The PL measurements showed a decrease in UV band intensity with dopant insertion, reflecting changes in excitonic recombination. PL deconvolution revealed an increase in zinc vacancies (VZn) from 42.04 % to 61.63 % and a reduction in neutral oxygen vacancies (Vo) from 46.95 % to 33.26 %, with Vo+ emissions detected only in the ZCR33 and ZCR35 samples. These results suggest that the Zn1-x-yCuxReyO compound is a promising material for optoelectronics. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Zinc oxide

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Self SOC Estimation for Second-Life Lithium-Ion Batteries

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IEEE Access 2025年 13卷 75033-75042页

作者： Gotz, Joelton Deonei Viana, Emilson Ribeiro Galvão, José Rodolfo Corrêa, Fernanda Cristina Borsato, Milton Badin, Alceu André Paraná Curitiba81280-340 Brazil Department of Computer Science Paraná Curitiba80215-901 Brazil Department of Physics Paraná Curitiba81280-340 Brazil Paraná Ponta Grossa80230-901 Brazil Postgraduate Program in Mechanical and Materials Engineering Paraná Curitiba81280-340 Brazil

Lithium-ion batteries (LIB) are the mainstream technology for energy storage in several industrial segments, such as mobility and stationary systems for solar, wind, or other alternative energy source. This technology has a long lifetime, low self-discharge, high capacity and density, and can store energy longer. Despite that, LIB is suitable to supply power for electric mobility if its state of health (SOH) is higher than 80%. Then, an alternative for batteries with SOH below that is recycling or second-life batteries (SLB). The first is expensive and complex;only some companies retain the technology. Still, the SLB can be an excellent solution to maintaining LIBs in operation for slow vehicles or stationary systems. However, SLB requires intelligent battery management systems (BMS) because the packs are composed of cells with different characteristics, which makes the operation more difficult. This work presents a system consisting of two Machine Learning (ML) layers to automatically estimate the state of charge (SOC) of SLB independent of the battery’s capacity or age. In the first phase, a Random Forest (RF) model was built and trained to discover the curve capacity of different SLB characteristics and capacities. After the capacity curve selection, in the second phase, a new RF model was built and trained for each capacity curve to make SOC inferences of the batteries. The discharge data curve of one hundred batteries was used for the development, whereas eighteen were used for the training and eighty-two for tests. The results indicated a root square mean error (RSME) below 45 mAh for the capacity estimation (phase 1), and an RSME below 0.87% was found in the second phase for the SOC estimation. Finally, the capacity and SOC models have been inserted in a Raspberry system to measure the main parameters of SLB (voltage and current) and make inferences in real time independent of the cell’s age. The results showed an RSME below 100 mAh for the first layer and be

关键词： Lithium-ion batteries

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Thermo-optical properties of erbium-doped germanate-bismuth glasses

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Optical Materials 2025年 166卷

作者： Silva, Adriano Almeida Lima, Lucas Batista Silva da Silva, Isis Lee Garcia, Hans Anderson Bell, Maria José Valenzuela Kassab, Luciana Reyes Pires Santos, Francisco Eroni Paz Postgraduate Program in Physics Federal University of Piauí PI 64049550 Brazil Department of Physics Federal University of Juiz de Fora MG Juiz de Fora36036-900 Brazil Faculdade de Tecnologia São Paulo CEETEPS SP São Paulo01124060 Brazil Postgraduate Program in Engineering and Materials Science Federal University of Teresina PI 64049550 Brazil

In this study, we investigate the thermo-optical properties of GeO2–Bi2O3 glasses doped with different concentrations of rare earth ions by thermal lens technique;UV-VIS and photoluminescence (PL) spectroscopy, as well as measurements of thermal diffusivity, thermal conductivity and quantum efficiency, are presented aiming at potential photonic applications. High infrared fluorescence lifetimes around 4 ms and quantum efficiencies of ∼80 % for 1 % Er3+ concentration, determined via lifetime and thermal lens methods, enabled efficient laser operation. Positive ds/dT values confirmed the self-focusing nature beneficial for high-power systems. While quantum efficiencies decreased exponentially with rising Er3+ due to non-radiative relaxation from erbium-matrix interactions, reasonably high efficiencies above 74 % persisted at 1 % doping. The thermal diffusivity and conductivity exhibited little changes with varying Er3+ concentration and showed to be matrix dependent. © 2025 Elsevier B.V.

关键词： Quantum efficiency

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New dynamic test rig to study the influence of ultrasound on calcium carbonate scale formation

Results in Engineering

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Results in Engineering 2025年 26卷

作者： Oliveira, Lucas R. Soares, Luiz C.S. Demetino, Geydison G. Soares, Lorena O.L. Gomes, Juliane G.C. da Silva, Marcus V.S. dos Santos, Vitor S. Teixeira, Leandro R. Santos, José M. de A. Ferreira, Vitor P. Pepe, Iuri M. Postgraduate Program in Mechatronics Federal University of Bahia - Salvador BA Brazil Bahia Cruz das Almas Brazil Institute of Physics Federal University of Bahia - UFBA Bahia Salvador Brazil Science Technology and Innovation Institute University of Bahia - UFBA Bahia Camaçari Brazil

Inorganic scale in oil and gas pipelines is a critical problem in the petrochemical industry, causing reduced flow in pipes and heat exchangers. Carbonates deposition is persistent and influenced by several factors such as temperature, pressure, and pH. This paper presents a Precipitation and Scaling Test Rig (PSTR) as an experimental platform to study the influence of ultrasound on calcium carbonate scale formation. This tool enables the investigation of the three main factors influencing inorganic scale formation (temperature, pressure, and pH) and allows experiments varying reagents flow rate, reagents concentration, and applying physical and chemical scale inhibitors during inorganic crystal formation reactions. To study the effects of ultrasound on calcium carbonate scale formation, two tests were performed: one without ultrasound irradiation and the other with ultrasound applied during the calcium carbonate crystallization process. In both cases, the same process parameters were used on the PSTR. The induction period was analyzed by measuring conductivity. The pressure drop across a deposition module was monitored. The results indicate that ultrasonic irradiation during crystallization accelerates crystal nucleation, prevents scale formation, and modifies the crystallographic phase of calcium carbonate crystals. Additionally, SEM images, composition, and phases of produced crystals showed changes in crystal morphology when ultrasound was applied. © 2025 The Authors

关键词： Crystallization

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Computational Characterization of the Recently Synthesized Pristine and Porous 12-Atom-Wide Armchair Graphene Nanoribbon

arXiv

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arXiv 2025年

作者： da Gomes, Djardiel S. Felix, Isaac M. Radel, Willian F. Dias, Alexandre C. Ribeiro Junior, Luiz A. Pereira Junior, Marcelo L. State University of Campinas Gleb Wataghin Institute of Physics Department of Applied Physics Campinas São Paulo13083-859 Brazil University of Brasília Faculty UnB Planaltina Materials Science Postgraduate Program Federal District Brasília Brazil Center for Agri-food Science and Technology Federal University of Campina Grande Paraíba Pombal58840-000 Brazil University of Brasília Institute of Physics Physics Postgraduate Program Federal District Brasília70910900 Brazil Institute of Physics International Center of Physics University of Brasília Federal District Brasília70910-900 Brazil Institute of Physics University of Brasília Federal District Brasília70910-900 Brazil Computational Materials Laboratory University of Brasília Federal District Brasília70910900 Brazil University of Brasília College of Technology Department of Electrical Engineering Federal District Brasília70910-900 Brazil

Recently synthesized Porous 12-Atom-Wide Armchair Graphene Nanoribbons (12-AGNRs) [Nano Lett. 2024, 24, 10718-10723]exhibit tunable properties through periodic porosity, enabling precise control over their electronic, optical, thermal, and mechanical behavior. This work presents a comprehensive theoretical characterization of pristine and porous 12-AGNRs based on density functional theory (DFT) and molecular dynamics (MD) simulations. DFT calculations reveal substantial electronic modifications, including band gap widening and the emergence of localized states. Analyzed within the Bethe–Salpeter equation (BSE) framework, optical properties highlight strong excitonic effects and significant absorption shifts. Thermal transport simulations indicate a pronounced reduction in conductivity due to enhanced phonon scattering at nanopores. At the same time, MD-based mechanical analysis shows decreased stiffness and strength while maintaining structural integrity. Despite these modifications, porous 12-AGNRs remain mechanically and thermally stable. These findings establish porosity engineering as a powerful strategy for tailoring graphene nanoribbons’ functional properties, reinforcing their potential for nanoelectronic, optoelectronic, and thermal management *** Codes 00-xx © 2025, CC BY.

关键词： Nanoribbons

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Thermo-optical properties of luminescent carbon dots produced from biomass of Orbignya speciosa (babassu coconut)

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Journal of Molecular Liquids 2025年 423卷

作者： Oliveira, Maykol Christian Damasceno Silva, Adriano Almeida Silva-Silva, Tânia Patrícia Silva, Jhaemely Gabrielly Vieira da Silva Júnior, José Ferreira Sanchez, David Bell, Maria José Valenzuela Garcia, Hans Anderson Viana, Bartolomeu Cruz Terrones, Mauricio Costa, Rubens Silva Santos, Francisco Eroni Paz Physics Department Federal University of Piauí PI 64049550 Brazil Postgraduate Program in Engineering and Materials Science Federal University of 64049550 PI Teresina Brazil Department of Physics and Center for 2-Dimensional and Layered Materials The Pennsylvania State University University ParkPA16802 United States Federal University of Juiz de Fora Institute of Exact Sciences Department of Physics University Campus - UFJF/ ICE/ Department of Physics Martelos MG Juiz de Fora36036330 Brazil Federal Institute of Piauí Paranaíba Campus PI Parnaíba64211145 Brazil

Exploring materials with high nonlinearities derived from organic and biological sources has become a significant focus within the scientific community. Among these materials, carbon dots (CDs) synthesized from biomass have emerged as promising candidates due to their sustainable and cost-effective production methods. This study synthesized CDs from Orbignya speciosa (babassu coconut) biomass via a hydrothermal route. UV–visible absorption and Infrared spectrum analysis revealed characteristic bands associated with the formation of dots and the electronic transitions π–π* from aromatic C=C bonds in the CDs’ core and n–π* transitions of surface carboxylate groups, photoluminescence as a function of temperature and lifetime decay measurements show that the photoluminescence mechanisms in these materials due this transitions comes from electronic indirect transitions from primary sources of the core and carbonyl boundings in the surface of the material, additionally, to this the Dynamic Light Scattering (DLS) and Transmission Electronic Microscopy (TEM) give the structural properties of the dots, amorphous and with a large size distribution with a mean size of (21 ± 1) nm. Thermal lens spectroscopy (TLS) was employed to determine the material's thermal diffusivity, reaching a maximum value of 2.03 × 10−7 m2/s as a function of dilution. The Z-scan technique under continuous wave (CW) excitation at 532 nm investigated nonlinear optical properties, yielding a maximum thermal nonlinear refractive index (n2(th)) value of −5.87 × 10−5 esu. Furthermore, the photothermal efficiency of the CDs was quantified at 505 nm, demonstrating a high absorption efficiency of 94.9 %, suggesting their potential application in photothermal therapies. These findings contribute to understanding babassu coconut CDs’ thermo-optical behavior, highlighting their promise for various practical applications, particularly in biomedicine. © 2025 Elsevier B.V.

关键词： Refractive index

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Evaluation of Maternal and Fetal S-Values from Iodine Isotopes in Nuclear Medicine Using the Monte Carlo Method

SSRN

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SSRN 2025年

作者： Coelho, Nathalia B.M. Alves, Arthur de Souza Borges Zuchet Santos, Carla J. Neves, Lúcio P. Perini, Ana P. Belinato, Walmir Ferreira, José Rafael S. Santos, William S. Postgraduate Program in Biomedical Engineering Faculty of Electrical Engineering Federal University of Uberlândia Uberlândia Brazil Institute of Physics Federal University of Uberlândia Uberlândia Brazil Federal Institute of Bahia - IFBA BA Vitória da Conquista Brazil Department of Physics Federal University of Sergipe São Cristóvão Brazil Universidade Federal da Bahia Brazil

The use of radionuclides for therapeutic and diagnostic purposes is the primary function of nuclear medicine. Among these radionuclides, the iodine family stands out as isotopes that can serve various purposes, including brachytherapy, scintigraphy, and research. The internal dosimetry of these nuclides becomes even more important when considering high-risk groups such as pregnant patients, as it involves concerns for both the mother and the fetus. This study aims to use Monte Carlo simulations to calculate S-values for a set of target organs in both the pregnant woman and the fetus, considering different source organs in the mother and three iodine isotopes: 131I, 125I, and 123I. The results indicated that 131I, with the highest emission energy, presented a high dose deposition pattern in target organs farther from the source organs, while 125I, with the lowest energy, showed a localized dose absorption pattern in adjacent organs. The highest S-values (all in mGy/MBq.s) were obtained for the pregnant woman, with values of 5.8E-05 in the thyroid using 123I and 125I, and 3.7E-04 in the bladder using 131I. For fetal organs, the most irradiated were the brain and skull using 131I, with values of 6.3E-06 and 5.6E-06, respectively, while the lowest values were associated with the use of 125I in source organs distant from the target organ, with contributions as low as 1E-12 for the thyroid as a source. This work presents a qualitative and quantitative study of the internal dosimetry of a pregnant patient and her fetus, addressing variables such as radioactive isotope and source and target organs, serving as a reference for dosimetric calculations deemed necessary in clinical practices to minimize the dose received by this critical group. © 2025, The Authors. All rights reserved.

关键词： Nuclear medicine

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Sm 2 O 3 -induced superconductivity enhancements in bulk Y-123 ceramics synthesized via a novel modified thermal decomposition method

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Journal of Materials Research and Technology 2025年 36卷 9168-9181页

作者： Ryad Alhadei Mohamed Arebat Mohd Mustafa Awang Kechik Yap Siew Hong Chen Soo Kien Lim Kean Pah Hussien Baqiah Fatma Barood Syahrul Humaidi Hoo Keong Peh Abdul Halim Shaari Muhammad Kashfi Shabdin Muralidhar Miryala Superconductor & Thin Films Laboratory Department of Physics Faculty of Science Universiti Putra Malaysia UPM Serdang 43400 Selangor Malaysia Department of Physics Faculty of Science El-Mergib University Al Khums City Libya Shandong Key Laboratory of Biophysics Institute of Biophysics Dezhou University No. 566 University Rd. West Dezhou Shandong China Department of Physics Faculty of Science Azzaytuna University Tarhuna City Libya Postgraduate Program (Physics) FMIPA Universitas Sumatera Utara Medan 20222 Indonesia Materials for Energy and Environmental Laboratory Superconducting Materials Shibaura Institute of Technology 3 Chome-7-5 Toyosu Koto Tokyo 135-8548 Japan

This study presents a novel modified thermal decomposition (MTD) technique for the synthesis of bulk YBa 2 Cu 3 O 7-δ (Y-123) ceramics with varying samarium oxide (Sm 2 O 3 ) additions (0.0,0.1,0.3,0.5, 1.0 and 5.0 wt%) under ambient conditions. A structural analysis via X-ray diffraction (XRD) with Rietveld refinement confirmed the dominant formation of the orthorhombic Y-123 phase, accompanied by minor secondary phases, such as Y 2 BaCuO 5 (Y-211) and BaCuO 2 . Notably, at 0.1 wt% Sm 2 O 3 , a distinct Sm 1.15 Ba 1.85 Cu 3 O 7 (Sm-123) phase emerged, contributing to enhanced phase stability and effective flux pinning. The optimized 0.1 wt% sample exhibited the highest oxygen content (∼6.87), largest crystallite size (∼1865 Å), and lowest lattice strain, factors directly linked to enhanced superconducting properties. Field emission scanning electron microscopy (FESEM) revealed significant grain growth (∼8.14 μm) and enhanced grain connectivity at 0.1 wt%, while higher doping levels caused porosity and microstructural deterioration. High-resolution imaging further revealed zigzag grain boundaries and nanoscale inclusions acting as flux pinning centers. Energy-dispersive X-ray spectroscopy (EDX) confirmed the uniform elemental distribution and successful Sm incorporation. The 0.1 wt% Sm 2 O 3 -added sample achieved the highest critical current density ( J c = 5.62 kA/cm 2 at 77 K), with a narrow superconducting transition width (Δ T c ≈ 2.96 K), a T c-onset of 92.21 K, and a T c-zero of 89.25 K, indicating minimal weak-link behavior. These findings demonstrate that low-level Sm 2 O 3 addition effectively introduces flux pinning centers while preserving crystal integrity and oxygen stoichiometry. The resulting enhancement in superconducting performance underscores the scalability and efficacy of the MTD route for producing high-performance Y-123 ceramics.

关键词： Y-123 ceramics Sm 2 O 3 addition Modified thermal decomposition (MTD) Phase formation Critical current density ( J c ) Superconductivity enhancement

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Spin pumping mechanism in Py/SnTe bilayers: An approach through the magnetoimpedance effect

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Journal of Alloys and Compounds 2025年 1031卷

作者： de Morais, A. Souza, E.C. de Silva, A.L. Gamino, M. da Silva, E.F. Ferreira, A. Vaz, F. Lopes, C. Bohn, F. Correa, M.A. Postgraduate Program in Materials Science and Engineering Federal University of Rio Grande do Norte RN Natal 59078-970 Brazil Physics Department Federal University of Rio Grande do Norte RN Natal 59075-000 Brazil Physics Department Federal University of Pernambuco PE Recife 50670-901 Brazil Physics Centre of Minho and Porto Universities (CF-UM-UP) University of Minho 4710-057 Portugal LaPMET - Laboratory of Physics for Materials and Emergent Technologies University of Minho 4710-057 Portugal

Different techniques addressing magnetization dynamics are helpful to estimate parameters of a ferromagnetic thin film nanostructure in the field of spintronics, including Gilbert damping parameter (α_G), spin pumping contributions (α_SP), two magnons scattering (α_TMS), spin mixing conductance (G_eff) and others. When considering a bilayer structure, the non-ferromagnetic layer effects need to be carefully selected to tailor an effective spintronic response. Here, the magnetization dynamics are explored in Ni₈₁Fe₁₉(Py)/Ag and Ni₈₁Fe₁₉(Py)/SnTe nanostructures and report the spin mixing conductance from magnetoimpedance experiments. The results are interpreted by considering structural and magnetic characterizations. The spin mixing conductance is estimated as G_eff (Py/Ag) = 1.13×10¹⁴ cm⁻² and G_eff (Py/SnTe) = 18.05 ×10¹⁴ cm⁻², revealing the significant enhancement of G_eff when the SnTe acts as a cap layer, indicating that SnTe is a good spin sink. © 2025 Elsevier B.V.

关键词： Damping mechanisms Magnetoimpedance SnTe Spin pumping Spintronics

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Ultrasensitive voltammetric sensor based on ferrocenium tetrachloroferrate for determination of manganese(II) in water pollutant

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Materials Chemistry and physics 2025年 339卷

作者： Nofriandi, Alwi Yulkifli Isa, Illyas Md Hashim, Norhayati Saidin, Mohamad Idris Ahmad, Mohamad Syahrizal Dewata, Indang Yohandri Mawardi Alizar Nuryadi, Ratno Doctoral Program of Environmental Science Postgraduate Program Universitas Negeri Padang Padang Air Tawar25132 Indonesia Department of Physics Faculty of Natural Science and Mathematics Universitas Negeri Padang Padang Air Tawar25132 Indonesia Department of Chemistry Faculty of Science and Mathematics Universiti Pendidikan Sultan Idris Perak Tanjong Malim35900 Malaysia Department of Chemistry Faculty of Natural Science and Mathematics Universitas Negeri Padang Padang Air Tawar25132 Indonesia Center of Materials Technology Agency for the Assessment and Aplication of Technology Banten15314 Indonesia

This study presents the development and characterization of a multi-walled carbon nanotubes (MWCNTs)-based paste electrode modified with ferrocenium tetrachloroferrate (FTCF) for detecting of manganese(II) ions, Mn(II) in environmental applications. The modified material was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy. Electrochemical performance was evaluated through cyclic voltammetry, electrochemical impedance spectroscopy, and chronocoulometry. Square wave voltammetry was employed for quantitative detection of Mn(II). The MWCNTs/FTCF electrode demonstrated a linear detection range from 1.0 nM to 0.1 μM and 1.0 μM to 0.1 mM, with correlation coefficients (R2) of 0.9865 and 0.9762, respectively, and a detection limit of 0.275 nM. Interference study towards 11 competing ions, each at 10 folds concentration of Mn(II) shown an interference levels below 15 %, indicating a good selectivity. Additionally, the electrode exhibited excellent stability and reproducibility. The proposed electrode has been applied to determine Mn(II) in real water samples and the results shown that recovery values from 93 % to 113 %. Hence, it was suggested as alternative tool for the analysis of Mn(II) in environmental study. © 2025 Elsevier B.V.

关键词： Fourier transform infrared spectroscopy

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