Pub Date : 2026-01-08DOI: 10.1016/j.tsf.2026.140855
Pukar Sedai , Arjun Sapkota , Allison Avery , Kaylee I. Perez , Robert M. Klaes , Reza Loloee , Nathan Satchell
We report a systematic study of the growth and characterization of niobium (Nb) thin films deposited at near room temperature on various sapphire and silicon substrates under different sputtering conditions, with the goal of optimizing deposition conditions and elucidating the relationship between structural quality and superconducting performance. X-ray reflectivity measurements indicate that films grown on C-plane sapphire exhibit low surface roughness, corresponding to smooth, uniform growth. X-ray diffraction analysis reveals that these films also display superior crystallinity, with sharper peaks and narrower full width at half maximum compared to films grown on A-plane, R-plane sapphire, and silicon substrates. Electrical transport measurements show a clear correlation between improved structural quality and higher superconducting critical temperature and increased coherence length. These results highlight the critical role of substrate choice and deposition parameters in determining the microstructural and superconducting properties of Nb thin films. Our findings offer guidance for optimizing Nb-based superconducting electrodes through careful substrate and process selection for near-room-temperature growth.
{"title":"Optimization of polycrystalline sputtered niobium thin films: The role of substrate and growth pressure","authors":"Pukar Sedai , Arjun Sapkota , Allison Avery , Kaylee I. Perez , Robert M. Klaes , Reza Loloee , Nathan Satchell","doi":"10.1016/j.tsf.2026.140855","DOIUrl":"10.1016/j.tsf.2026.140855","url":null,"abstract":"<div><div>We report a systematic study of the growth and characterization of niobium (Nb) thin films deposited at near room temperature on various sapphire and silicon substrates under different sputtering conditions, with the goal of optimizing deposition conditions and elucidating the relationship between structural quality and superconducting performance. X-ray reflectivity measurements indicate that films grown on C-plane sapphire exhibit low surface roughness, corresponding to smooth, uniform growth. X-ray diffraction analysis reveals that these films also display superior crystallinity, with sharper peaks and narrower full width at half maximum compared to films grown on A-plane, R-plane sapphire, and silicon substrates. Electrical transport measurements show a clear correlation between improved structural quality and higher superconducting critical temperature and increased coherence length. These results highlight the critical role of substrate choice and deposition parameters in determining the microstructural and superconducting properties of Nb thin films. Our findings offer guidance for optimizing Nb-based superconducting electrodes through careful substrate and process selection for near-room-temperature growth.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"834 ","pages":"Article 140855"},"PeriodicalIF":2.0,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928007","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}
This work investigates the synthesis, characterization, and tribological performance of bi- and few-layer graphene using copper substrates as catalysts. Two types of copper substrates were employed: bulk copper foils (0.25 mm thickness) and thin copper films (∼800 nm thickness) deposited by magnetron sputtering. Bilayer amorphous-carbon/copper (a-C/Cu) and copper/amorphous-carbon (Cu/a-C) films were also produced as solid-carbon-source substrates. Graphene formation occurred via two distinct thermal processes: (1) catalytic chemical vapor deposition (CVD) on bulk copper foils and on copper films without amorphous carbon, using methane as the carbon precursor under Ar–H₂ atmospheres; and (2) annealing of a-C/Cu and Cu/a-C films under H₂–Ar without methane, in which graphene forms by carbon diffusion from the solid source. Raman spectroscopy confirmed the presence of bi- and few-layer graphene, revealing variations in layer number, crystallinity, and structural disorder. Atomic force microscopy (AFM) lateral-friction mapping showed local friction reduction in graphene-covered regions, confirming its role in modulating nanoscale tribological response. Macroscale sliding tests under normal loads of 0.5–2 N revealed load-dependent behavior: the lowest load yielded a stable low friction coefficient (∼0.18), whereas higher loads increased friction (up to 0.35) and wear rates due to progressive graphene removal. Raman analysis of the worn tracks showed loss of the 2D band, increased D-band intensity, and the emergence of D + G features, indicating disorder, amorphization, and partial oxidation of the exposed copper substrate. The results demonstrate that although graphene initially reduces friction and protects the surface, prolonged load-bearing contact is governed by the stability of its ultrathin layers.
{"title":"Synthesis of Graphene on catalyst copper substrates: Growth mechanisms and friction behavior","authors":"M.F.C. Ordoñez , D.J. Feria , I. Pereyra , M.N.P. Carreño , R.M. Souza , A.P. Tschiptschin","doi":"10.1016/j.tsf.2026.140852","DOIUrl":"10.1016/j.tsf.2026.140852","url":null,"abstract":"<div><div>This work investigates the synthesis, characterization, and tribological performance of bi- and few-layer graphene using copper substrates as catalysts. Two types of copper substrates were employed: bulk copper foils (0.25 mm thickness) and thin copper films (∼800 nm thickness) deposited by magnetron sputtering. Bilayer amorphous-carbon/copper (a-C/Cu) and copper/amorphous-carbon (Cu/a-C) films were also produced as solid-carbon-source substrates. Graphene formation occurred via two distinct thermal processes: (1) catalytic chemical vapor deposition (CVD) on bulk copper foils and on copper films without amorphous carbon, using methane as the carbon precursor under Ar–H₂ atmospheres; and (2) annealing of a-C/Cu and Cu/a-C films under H₂–Ar without methane, in which graphene forms by carbon diffusion from the solid source. Raman spectroscopy confirmed the presence of bi- and few-layer graphene, revealing variations in layer number, crystallinity, and structural disorder. Atomic force microscopy (AFM) lateral-friction mapping showed local friction reduction in graphene-covered regions, confirming its role in modulating nanoscale tribological response. Macroscale sliding tests under normal loads of 0.5–2 N revealed load-dependent behavior: the lowest load yielded a stable low friction coefficient (∼0.18), whereas higher loads increased friction (up to 0.35) and wear rates due to progressive graphene removal. Raman analysis of the worn tracks showed loss of the 2D band, increased D-band intensity, and the emergence of D + G features, indicating disorder, amorphization, and partial oxidation of the exposed copper substrate. The results demonstrate that although graphene initially reduces friction and protects the surface, prolonged load-bearing contact is governed by the stability of its ultrathin layers.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"834 ","pages":"Article 140852"},"PeriodicalIF":2.0,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928010","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}
Pub Date : 2026-01-01DOI: 10.1016/j.tsf.2025.140845
Minh-Anh Tran Nguyen , Anh Tuan Duong , Sunglae Cho
In this study, we demonstrate the evidence of composition-driven control of in-plane magnetic anisotropy in Fe100-xGax epitaxial films with Ga concentrations ranging from 0 to 30 %. Epitaxial Fe100-xGax thin films were grown on MgO(100) substrates by molecular beam epitaxy (MBE). Crystalline quality gradually degrades as Ga content increases. The out-of-plane lattice parameter expands systematically with Ga substitution, reflecting lattice distortion due to the larger atomic radius of Ga. Magnetic measurements reveal a monotonic reduction in saturation magnetization and a pronounced increase in coercivity with increasing Ga content, while electrical transport demonstrates a corresponding rise in resistivity. Most notably, pure Fe exhibits sharp fourfold anisotropy with well-defined easy axes, which becomes progressively weakened at intermediate Ga levels and evolves into nearly isotropic behavior at 30 at. % Ga. These results shown that the in-plane magnetic anisotropy of Fe100-xGax epitaxial films can be systematically tuned by composition, bridging bulk magnetostriction studies and thin-film spintronic applications, and offering a route to engineer anisotropy symmetry for functional device application.
{"title":"Modulation of in-plane magnetic anisotropy in FeGa alloy epitaxial films with Ga content","authors":"Minh-Anh Tran Nguyen , Anh Tuan Duong , Sunglae Cho","doi":"10.1016/j.tsf.2025.140845","DOIUrl":"10.1016/j.tsf.2025.140845","url":null,"abstract":"<div><div>In this study, we demonstrate the evidence of composition-driven control of in-plane magnetic anisotropy in Fe<sub>100-x</sub>Ga<sub>x</sub> epitaxial films with Ga concentrations ranging from 0 to 30 %. Epitaxial Fe<sub>100-x</sub>Ga<sub>x</sub> thin films were grown on MgO(100) substrates by molecular beam epitaxy (MBE). Crystalline quality gradually degrades as Ga content increases. The out-of-plane lattice parameter expands systematically with Ga substitution, reflecting lattice distortion due to the larger atomic radius of Ga. Magnetic measurements reveal a monotonic reduction in saturation magnetization and a pronounced increase in coercivity with increasing Ga content, while electrical transport demonstrates a corresponding rise in resistivity. Most notably, pure Fe exhibits sharp fourfold anisotropy with well-defined easy axes, which becomes progressively weakened at intermediate Ga levels and evolves into nearly isotropic behavior at 30 at. % Ga. These results shown that the in-plane magnetic anisotropy of Fe<sub>100-x</sub>Ga<sub>x</sub> epitaxial films can be systematically tuned by composition, bridging bulk magnetostriction studies and thin-film spintronic applications, and offering a route to engineer anisotropy symmetry for functional device application.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"833 ","pages":"Article 140845"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883925","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}
Pub Date : 2026-01-01DOI: 10.1016/j.tsf.2025.140850
Sachin Sachin, Ajay Kumar
High entropy alloys (HEAs) are advanced materials which have been in research focus for over two decades. AlCoCrCuFeNiTi is one such HEA which have been studied and synthesized in bulk with excellent mechanical properties but not studied in thin film. This work explores the synthesis of AlCoCrCuFeNiTi thin films via co-sputtering on a magnetron sputtering setup using three targets namely Al, CoCrCuFeNi and Ti targets as the magnetron sputtering allows to synthesize thin film in high vacuum which result in high quality films. Three different thin films have been synthesized on Si substrates at room temperature. The films synthesized were found to have broad X-ray diffraction peak and appeared as low crystalline films, resulting due to high quenching rate at room temperature deposition, high negative mixing enthalpy, and significant atomic mismatch due to larger Al and Ti atoms. The thermodynamic parameters of the films are evaluated using the various equations and the synthesized films HEAs are predicted to be a solid solution. The film's surface morphology is studied by atomic force microscopy and scanning electron microscopy and the films had cauliflower-like cluster agglomeration and nano cracks with the highest average width of 16 ± 5.1 nm. The films are also studied for mechanical properties using nanoindentation, and the maximum hardness of 3.35 GPa and Young’s modulus of 105.13 GPa was achieved. The present work is an attempt to investigate HEAs thin films synthesized via magnetron sputtering (co-sputtering), as the AlCoCrCuFeNiTi system of HEAs have not been fabricated in thin film form. This work could also encourage more research into the co-sputtering method of synthesis of more complex HEAs.
{"title":"Ti-rich thin film synthesis of AlCoCrCuFeNiTi high entropy alloy via magnetron co-sputtering and its mechanical properties","authors":"Sachin Sachin, Ajay Kumar","doi":"10.1016/j.tsf.2025.140850","DOIUrl":"10.1016/j.tsf.2025.140850","url":null,"abstract":"<div><div>High entropy alloys (HEAs) are advanced materials which have been in research focus for over two decades. AlCoCrCuFeNiTi is one such HEA which have been studied and synthesized in bulk with excellent mechanical properties but not studied in thin film. This work explores the synthesis of AlCoCrCuFeNiTi thin films via co-sputtering on a magnetron sputtering setup using three targets namely Al, CoCrCuFeNi and Ti targets as the magnetron sputtering allows to synthesize thin film in high vacuum which result in high quality films. Three different thin films have been synthesized on Si substrates at room temperature. The films synthesized were found to have broad X-ray diffraction peak and appeared as low crystalline films, resulting due to high quenching rate at room temperature deposition, high negative mixing enthalpy, and significant atomic mismatch due to larger Al and Ti atoms. The thermodynamic parameters of the films are evaluated using the various equations and the synthesized films HEAs are predicted to be a solid solution. The film's surface morphology is studied by atomic force microscopy and scanning electron microscopy and the films had cauliflower-like cluster agglomeration and nano cracks with the highest average width of 16 ± 5.1 nm. The films are also studied for mechanical properties using nanoindentation, and the maximum hardness of 3.35 GPa and Young’s modulus of 105.13 GPa was achieved. The present work is an attempt to investigate HEAs thin films synthesized via magnetron sputtering (co-sputtering), as the AlCoCrCuFeNiTi system of HEAs have not been fabricated in thin film form. This work could also encourage more research into the co-sputtering method of synthesis of more complex HEAs.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"834 ","pages":"Article 140850"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928009","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}
Pub Date : 2026-01-01DOI: 10.1016/j.tsf.2025.140846
Jakub Zdziebłowski , Marek Pawłowski , Cezariusz Jastrzębski , Nicolas Barreau , Paweł Zabierowski
The optoelectronic properties of cadmium-indium thiospinel (CdIn₂S₄) thin films are critically influenced by structural defects, particularly the degree of spinel inversion, which is essential for tuning their performance in photocatalysis and photovoltaics. This study systematically investigates how controlled post-deposition treatments affect the inversion degree, sulfur vacancy concentration, and, consequently, the fundamental electronic properties of CdIn₂S₄, including bandgap, conductivity, and photoluminescence characteristics. Our experimental findings provide clear evidence supporting theoretical predictions regarding the dependency of bandgap energy on the inversion degree. We observed a total increase of the bandgap energy by up to 0,2 eV due to spinel inversion reduction. Additionally, we highlight the significant influence of sulfur vacancy-related defects, which notably impact the electronic structure and defect state dynamics within the material. By manipulating spinel inversion through post-deposition treatment (PDT), we observe upon prolonged vacuum annealing at 300 °C the repining of the Fermi level from 0,1 eV to 0,4 eV below conduction band minimum (CBM) and further down to 0,7 eV below CBM by annealing in sulfur atmosphere. By controlling spinel inversion and sulfur vacancy defects through annealing under varied conditions, we offer valuable insights into the intricate relationship between structural imperfections and electronic properties. These insights contribute to the targeted optimization of CdIn2S4 and related chalcogenide semiconductors, aiding researchers in developing more efficient materials for solar energy harvesting and photocatalytic applications.
{"title":"Influence of post deposition treatment on optoelectronic properties of CdIn2S4","authors":"Jakub Zdziebłowski , Marek Pawłowski , Cezariusz Jastrzębski , Nicolas Barreau , Paweł Zabierowski","doi":"10.1016/j.tsf.2025.140846","DOIUrl":"10.1016/j.tsf.2025.140846","url":null,"abstract":"<div><div>The optoelectronic properties of cadmium-indium thiospinel (CdIn₂S₄) thin films are critically influenced by structural defects, particularly the degree of spinel inversion, which is essential for tuning their performance in photocatalysis and photovoltaics. This study systematically investigates how controlled post-deposition treatments affect the inversion degree, sulfur vacancy concentration, and, consequently, the fundamental electronic properties of CdIn₂S₄, including bandgap, conductivity, and photoluminescence characteristics. Our experimental findings provide clear evidence supporting theoretical predictions regarding the dependency of bandgap energy on the inversion degree. We observed a total increase of the bandgap energy by up to 0,2 eV due to spinel inversion reduction. Additionally, we highlight the significant influence of sulfur vacancy-related defects, which notably impact the electronic structure and defect state dynamics within the material. By manipulating spinel inversion through post-deposition treatment (PDT), we observe upon prolonged vacuum annealing at 300 °C the repining of the Fermi level from 0,1 eV to 0,4 eV below conduction band minimum (CBM) and further down to 0,7 eV below CBM by annealing in sulfur atmosphere. By controlling spinel inversion and sulfur vacancy defects through annealing under varied conditions, we offer valuable insights into the intricate relationship between structural imperfections and electronic properties. These insights contribute to the targeted optimization of CdIn<sub>2</sub>S<sub>4</sub> and related chalcogenide semiconductors, aiding researchers in developing more efficient materials for solar energy harvesting and photocatalytic applications.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"833 ","pages":"Article 140846"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883923","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}
Ag-Si composite films containing silver nanoparticles are employed in memristor structures, substrates for surface-enhanced Raman spectroscopy, lithium-ion battery anodes, and various optoelectronic devices. However, metastable phases may emerge during the synthesis of Ag-Si films and strongly influence their properties. This study demonstrates the potential of ultra-soft X-ray emission spectroscopy (USXES) to identify metastable phases in AgxSi1-x films obtained by ion-beam sputtering. The results show that silver nanoparticles 10–30 nm in size are formed in AgxSi1-x films, which aggregate into conglomerates ∼200–400 nm in size, separated by a dielectric matrix based on silicon dioxide and SiOx silicon suboxides. USXES data combined with theoretical calculations reveal the presence of the metastable Ag2Si compound (Cmcm, 63) in AgxSi1-x films. The Ag2Si content increases from 10 to 30% as the Si content increases from 20 to 45 at.%. Furthermore, an abrupt increase in resistivity is observed from ∼5 × 10–5 to ∼10–3 Ω × cm. Moreover, due to their complex microstructure, AgxSi1-x films exhibit a memristive switching effect at 0,2 V, transitioning from a high-resistance state (∼1 kΩ) to a low-resistance state (∼1 Ω).
{"title":"Silicon-induced phase evolution and electrical switching in AgxSi1-x nanocomposite films synthesized by ion-beam sputtering","authors":"K.A. Barkov , V.V. Babakov , S.A. Ivkov , G.P. Potudanskii , A.I. Chukavin , Y.A. Peshkov , M.V. Grechkina , K.E. Velichko , I.E. Zanin , S.V. Kannykin , B.L. Agapov , S.V. Rodivilov , E.S. Kersnovsky , I.V. Polshin , N.S. Buylov , V.V. Pobedinsky , D.N. Nesterov , Tran Van Tu , A.E. Nikonov , A.V. Sitnikov","doi":"10.1016/j.tsf.2025.140847","DOIUrl":"10.1016/j.tsf.2025.140847","url":null,"abstract":"<div><div>Ag-Si composite films containing silver nanoparticles are employed in memristor structures, substrates for surface-enhanced Raman spectroscopy, lithium-ion battery anodes, and various optoelectronic devices. However, metastable phases may emerge during the synthesis of Ag-Si films and strongly influence their properties. This study demonstrates the potential of ultra-soft X-ray emission spectroscopy (USXES) to identify metastable phases in Ag<sub>x</sub>Si<sub>1-x</sub> films obtained by ion-beam sputtering. The results show that silver nanoparticles 10–30 nm in size are formed in Ag<sub>x</sub>Si<sub>1-x</sub> films, which aggregate into conglomerates ∼200–400 nm in size, separated by a dielectric matrix based on silicon dioxide and SiO<sub>x</sub> silicon suboxides. USXES data combined with theoretical calculations reveal the presence of the metastable Ag<sub>2</sub>Si compound <em>(Cmcm, 63)</em> in Ag<sub>x</sub>Si<sub>1-x</sub> films. The Ag<sub>2</sub>Si content increases from 10 to 30% as the Si content increases from 20 to 45 at.%. Furthermore, an abrupt increase in resistivity is observed from ∼5 × 10<sup>–5</sup> to ∼10<sup>–3</sup> Ω × cm. Moreover, due to their complex microstructure, Ag<sub>x</sub>Si<sub>1-x</sub> films exhibit a memristive switching effect at 0,2 V, transitioning from a high-resistance state (∼1 kΩ) to a low-resistance state (∼1 Ω).</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"833 ","pages":"Article 140847"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883924","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}
To address the urgent demands of sub-3 nm semiconductor node fabrication in advanced logic and three-dimensional flash memory architectures, we developed tungsten-doped amorphous carbon (WDC) hardmasks by plasma-enhanced chemical vapor deposition (PECVD) employing propylene (C3H6) and tungsten hexafluoride (WF6) precursors. Systematic modulation of WF6 flow rates (0-320 sccm) achieved tungsten incorporation up to 40 at%, resulting in remarkable material property enhancements. X-ray reflectometry and nanoindentation confirmed a 6-fold density increase (1.36 to 8.24 g/cm³) and 3.3-fold hardness improvement (3.2 to 10.5 GPa). Mechanistically, X-ray photoelectron spectroscopy (XPS) analysis revealed predominant C-W bonds (283.5 eV), while high-resolution transmission electron microscopy (HRTEM) unveiled 3-4 nm tungsten carbide (WC1-x) nanocrystallites that simultaneously enhance structural integrity and fluorocarbon plasma resistance. The optimized composition demonstrated superior etch resistance with 55% reduced etch rate, accompanied by modulus enhancement to 125 GPa and controlled surface roughness (2.5 to 3.8 nm). This scalable, tunable approach advances hardmask technology for extreme ultraviolet lithography and next-generation memory devices.
Pub Date : 2025-12-30DOI: 10.1016/j.tsf.2025.140849
Houze Zhou , Wencong Deng , Qi Wang , Rui Liang , Danqian Wang
A phosphate-intercalated layered double hydroxide (PO4-LDH) coating was fabricated on carbon steel via a facile one-step electrodeposition method for enhanced corrosion protection. The resulting nanoscale coating, incorporating PO₄³⁻ ions and Cu/Al oxides, exhibits improved integrity and compactness. Electrochemical tests in saturated Ca(OH)₂ solution (simulating concrete pore environment) demonstrated that the PO4-LDH coating significantly improves corrosion resistance, offering protection two orders of magnitude greater than bare steel. The coating effectively prevents corrosion upon chloride attack and exhibits self-healing capability for artificial scratches in chloride-containing solution. During immersion, the LDH structure reconstructs via dissolution of Al and incorporation of Ca, leading to increased crystallinity. The release of inhibitor ions (PO₄³⁻ and NO₃⁻) during this reconstruction is considered the key mechanism for the observed anticorrosion and self-healing performance.
{"title":"Self-healing anticorrosion one-step electrodeposited layered double hydroxide coating on steel rebar in concrete pore solution","authors":"Houze Zhou , Wencong Deng , Qi Wang , Rui Liang , Danqian Wang","doi":"10.1016/j.tsf.2025.140849","DOIUrl":"10.1016/j.tsf.2025.140849","url":null,"abstract":"<div><div>A phosphate-intercalated layered double hydroxide (PO<sub>4</sub>-LDH) coating was fabricated on carbon steel via a facile one-step electrodeposition method for enhanced corrosion protection. The resulting nanoscale coating, incorporating PO₄³⁻ ions and Cu/Al oxides, exhibits improved integrity and compactness. Electrochemical tests in saturated Ca(OH)₂ solution (simulating concrete pore environment) demonstrated that the PO<sub>4</sub>-LDH coating significantly improves corrosion resistance, offering protection two orders of magnitude greater than bare steel. The coating effectively prevents corrosion upon chloride attack and exhibits self-healing capability for artificial scratches in chloride-containing solution. During immersion, the LDH structure reconstructs via dissolution of Al and incorporation of Ca, leading to increased crystallinity. The release of inhibitor ions (PO₄³⁻ and NO₃⁻) during this reconstruction is considered the key mechanism for the observed anticorrosion and self-healing performance.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"834 ","pages":"Article 140849"},"PeriodicalIF":2.0,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145875368","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}
Pub Date : 2025-12-20DOI: 10.1016/j.tsf.2025.140843
Manuel G. Pinedo-Cuba , Renzo Rueda-Vellasmín , Justiniano Quispe-Marcatoma , Carlos V. Landauro , Valberto P. Nascimento , Noemi R. Checca-Huamán , Víctor A. Peña-Rodríguez , Edson C. Passamani
In thin film growth, temperature is a key parameter that typically improves crystal quality. However, the temperature also promotes diffusion in the film-substrate interface. The present study investigated the effect of the substrate temperature () on the crystal ordering and magnetic properties of Ni-Mn-Sn-Pd pseudo-Heusler alloy thin films. Different chemical orderings were gradually observed in the films as a result of varying , with the following sequence: a dominant cubic A2-type structure found in the film prepared at 300 K, a presence of B32a-type structure in the film deposited at 673 K, and a mixture of B2 and structures in the film produced at 873 K. Besides the enhancement of atomic ordering with rising , an increase in the grain size of the cubic phases was also noted, both factors directly contributing to the observed improvements in the magnetic properties of the Ni-Mn-Sn-Pd films. All the films showed a magneto-structural phase transition at approximately regardless of the value. It was also shown that at , Ni atoms diffused into the Si substrate up to 27 nm, passing through buffer layers, i.e., and natural SiO2. This study demonstrates that the highest Ts favoured significant improvements on magneto-structural properties, but also promotes an undesired strong diffusion of Ni into the Si substrates.
{"title":"Influence of growth temperature on interface diffusion and magnetic properties of Ni-Mn-Sn-Pd thin films","authors":"Manuel G. Pinedo-Cuba , Renzo Rueda-Vellasmín , Justiniano Quispe-Marcatoma , Carlos V. Landauro , Valberto P. Nascimento , Noemi R. Checca-Huamán , Víctor A. Peña-Rodríguez , Edson C. Passamani","doi":"10.1016/j.tsf.2025.140843","DOIUrl":"10.1016/j.tsf.2025.140843","url":null,"abstract":"<div><div>In thin film growth, temperature is a key parameter that typically improves crystal quality. However, the temperature also promotes diffusion in the film-substrate interface. The present study investigated the effect of the substrate temperature (<span><math><msub><mi>T</mi><mi>S</mi></msub></math></span>) on the crystal ordering and magnetic properties of Ni-Mn-Sn-Pd pseudo-Heusler alloy thin films. Different chemical orderings were gradually observed in the films as a result of varying <span><math><msub><mi>T</mi><mi>S</mi></msub></math></span>, with the following sequence: a dominant cubic A2-type structure found in the film prepared at 300 K, a presence of B32a-type structure in the film deposited at 673 K, and a mixture of B2 and <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span> structures in the film produced at 873 K. Besides the enhancement of atomic ordering with rising <span><math><msub><mi>T</mi><mi>S</mi></msub></math></span>, an increase in the grain size of the cubic phases was also noted, both factors directly contributing to the observed improvements in the magnetic properties of the Ni-Mn-Sn-Pd films. All the films showed a magneto-structural phase transition at approximately <span><math><mrow><mn>50</mn><mspace></mspace><mi>K</mi></mrow></math></span> regardless of the <span><math><msub><mi>T</mi><mi>S</mi></msub></math></span> value. It was also shown that at <span><math><mrow><msub><mi>T</mi><mi>S</mi></msub><mo>=</mo><mn>873</mn><mspace></mspace><mi>K</mi></mrow></math></span>, Ni atoms diffused into the Si substrate up to 27 nm, passing through buffer layers, i.e., <span><math><mtext>Pt</mtext></math></span> and natural SiO<sub>2</sub>. This study demonstrates that the highest <em>T</em><sub>s</sub> favoured significant improvements on magneto-structural properties, but also promotes an undesired strong diffusion of Ni into the Si substrates.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"833 ","pages":"Article 140843"},"PeriodicalIF":2.0,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840214","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}
Pub Date : 2025-12-20DOI: 10.1016/j.tsf.2025.140844
A.I.A. Ali , F. Taghizadeh , P. J. Janse van Ransburg , W.E. Meyer , J.M. Nel , A. Venter
This paper reports on the presence of deep-level defects in polycrystalline GaN thin films induced during the sputter deposition of Au Schottky barrier diodes (SBDs). The n-GaN films, with a thickness of approximately 300 nm were electrodeposited on (111) Si substrates using a low-cost method and a current density of 3 mA.cm-2 for 3 hours. Structural analysis by X-ray diffraction, scanning electron microscopy, and atomic force microscopy confirmed the polycrystalline nature and good quality of the films. Deep-level transient spectroscopy (DLTS) revealed a broad, asymmetric peak around 265 K in the as-deposited SBDs, indicating the presence of multiple defects. Laplace DLTS resolved four distinct defects with energies ranging between 0.40 eV and 0.60 eV. Thermal annealing between 450 - 500 K increased the reverse leakage current with only minor changes in the forward-bias characteristics. However, annealing at 550 K significantly reduced the leakage current by two orders of magnitude and improved the rectification ratio by one order of magnitude. All samples exhibited significant series resistance. Capacitance-voltage measurements revealed a reduction in the free carrier density near the surface, suggesting the sputter process introduced additional deep level defects. Furthermore, the deep-level energy (and therefore the likely defect composition) was found to be sensitive to the annealing temperature.
{"title":"Electrical characterization of sputter-induced deep levels in GaN thin films synthesized by electrodeposition","authors":"A.I.A. Ali , F. Taghizadeh , P. J. Janse van Ransburg , W.E. Meyer , J.M. Nel , A. Venter","doi":"10.1016/j.tsf.2025.140844","DOIUrl":"10.1016/j.tsf.2025.140844","url":null,"abstract":"<div><div>This paper reports on the presence of deep-level defects in polycrystalline GaN thin films induced during the sputter deposition of Au Schottky barrier diodes (SBDs). The n-GaN films, with a thickness of approximately 300 nm were electrodeposited on (111) Si substrates using a low-cost method and a current density of 3 mA.cm<sup>-2</sup> for 3 hours. Structural analysis by X-ray diffraction, scanning electron microscopy, and atomic force microscopy confirmed the polycrystalline nature and good quality of the films. Deep-level transient spectroscopy (DLTS) revealed a broad, asymmetric peak around 265 K in the as-deposited SBDs, indicating the presence of multiple defects. Laplace DLTS resolved four distinct defects with energies ranging between 0.40 eV and 0.60 eV. Thermal annealing between 450 - 500 K increased the reverse leakage current with only minor changes in the forward-bias characteristics. However, annealing at 550 K significantly reduced the leakage current by two orders of magnitude and improved the rectification ratio by one order of magnitude. All samples exhibited significant series resistance. Capacitance-voltage measurements revealed a reduction in the free carrier density near the surface, suggesting the sputter process introduced additional deep level defects. Furthermore, the deep-level energy (and therefore the likely defect composition) was found to be sensitive to the annealing temperature.</div></div>","PeriodicalId":23182,"journal":{"name":"Thin Solid Films","volume":"833 ","pages":"Article 140844"},"PeriodicalIF":2.0,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840319","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}
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