Pub Date : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.305
Lihong Liu , Ming Yang , Bo Li , Duo zhang , Lihua Huo
In this paper, Au-modified Co3O4 hollow nanospheres/graphene composites (Au-Co3O4/rGO) were synthesized for the first time through a novel “one-pot cooking” method at ambient temperature. The hollow nanospheres exhibited a particle size of approximately 10–15 nm, while the modified Au nanoparticles were about 4–5 nm in diameter. A high-efficiency and high response H2S gas sensor was constructed based on Au-Co3O4/rGO ternary composites. The effects of different Au modifying mass ratios on the H2S gas-sensitive performance of the composites were systematically investigated. At an operational temperature of 92 °C, the Au-Co3O4/rGO sensor, incorporating an Au loading mass ratio of 1.3 wt%, exhibited a response value of 175.4 for H2S at 100 ppm, a recovery time of 30 s, and a detection limit reaching as low as 10 ppb. This response was tripled compared to the undoped Co3O4/rGO sensor. At the same time, the H2S sensing mechanism by Au-Co3O4/rGO was discussed in detail.
{"title":"Prepared gold-modified hollow nanosphere Co3O4/rGO composites for low concentration H2S gas detection","authors":"Lihong Liu , Ming Yang , Bo Li , Duo zhang , Lihua Huo","doi":"10.1016/j.ceramint.2024.09.305","DOIUrl":"10.1016/j.ceramint.2024.09.305","url":null,"abstract":"<div><div>In this paper, Au-modified Co<sub>3</sub>O<sub>4</sub> hollow nanospheres/graphene composites (Au-Co<sub>3</sub>O<sub>4</sub>/rGO) were synthesized for the first time through a novel “one-pot cooking” method at ambient temperature. The hollow nanospheres exhibited a particle size of approximately 10–15 nm, while the modified Au nanoparticles were about 4–5 nm in diameter. A high-efficiency and high response H<sub>2</sub>S gas sensor was constructed based on Au-Co<sub>3</sub>O<sub>4</sub>/rGO ternary composites. The effects of different Au modifying mass ratios on the H<sub>2</sub>S gas-sensitive performance of the composites were systematically investigated. At an operational temperature of 92 °C, the Au-Co<sub>3</sub>O<sub>4</sub>/rGO sensor, incorporating an Au loading mass ratio of 1.3 wt%, exhibited a response value of 175.4 for H<sub>2</sub>S at 100 ppm, a recovery time of 30 s, and a detection limit reaching as low as 10 ppb. This response was tripled compared to the undoped Co<sub>3</sub>O<sub>4</sub>/rGO sensor. At the same time, the H<sub>2</sub>S sensing mechanism by Au-Co<sub>3</sub>O<sub>4</sub>/rGO was discussed in detail.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49600-49609"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.328
Panting Wang , Mingjun Zhao , Weichang Li , Danping Chen
A Cu+ doped high alumina borosilicate glass with long persistent luminescence (LPL) was prepared by reduction melting and radiation induction based on glass defect engineering. The maximum time of the persistent luminescence can arrive 16 h. Spectral and EPR measurements indicate that two kinds of oxygen defects can be induced by X-ray radiation. One defect was eliminated after UV irradiation, and the other can synergistically participate in the LPL process of glass with reduction induced oxygen deficiency centers(ODCs). In addition, there is a highly linear relationship between the initial LPL intensity of the glass and the radiation dose; which implies the glass can be used as a radiation detection material. The internal mechanism of the linear relationship and LPL was discussed.
{"title":"X-ray-induced long persistent luminescence of Cu+-doped high alumina borosilicate glass","authors":"Panting Wang , Mingjun Zhao , Weichang Li , Danping Chen","doi":"10.1016/j.ceramint.2024.09.328","DOIUrl":"10.1016/j.ceramint.2024.09.328","url":null,"abstract":"<div><div>A Cu<sup>+</sup> doped high alumina borosilicate glass with long persistent luminescence (LPL) was prepared by reduction melting and radiation induction based on glass defect engineering. The maximum time of the persistent luminescence can arrive 16 h. Spectral and EPR measurements indicate that two kinds of oxygen defects can be induced by X-ray radiation. One defect was eliminated after UV irradiation, and the other can synergistically participate in the LPL process of glass with reduction induced oxygen deficiency centers(ODCs). In addition, there is a highly linear relationship between the initial LPL intensity of the glass and the radiation dose; which implies the glass can be used as a radiation detection material. The internal mechanism of the linear relationship and LPL was discussed.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49846-49852"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.300
Anna A. Melentsova, Olga A. Lipina, Alexander Yu. Chufarov, Alexander P. Tyutyunnik, Vladimir G. Zubkov
Two series of NaY0.85Tm0.15-xHoxGeO4 (x = 0.005–0.03) and NaY0.85-xTm0.15HoxGeO4 (x = 0.0–0.055) phosphors have been prepared by the citrate technique. According to XRPD study, all the germanates crystallize in olivine structure and have an orthorhombic lattice, space group Pnma, Z = 4. The diffuse reflectance spectra have been measured and the optical band gap has been estimated. Under 808 nm laser diode excitation, the NaYGeO4:Tm3+, Ho3+ samples exhibit luminescence in the range of 1640–2240 nm, which is caused by 3F4 → 3H6 transition in Tm3+ and 5I7 → 5I8 transition in Ho3+ ions. The highest intensity of holmium lines, while maintaining relatively high intensity of thulium lines, was observed for NaY0.82Tm0.15Ho0.03GeO4, NaY0.815Tm0.15Ho0.035GeO4 samples with the Tm3+/Ho3+ ratio close to 5/1. The luminescence decay kinetics has been studied and the rate of energy transfer from Tm3+ to Ho3+ ions has been calculated. The obtained results indicate an effective energy transfer accelerated by migration due to dipole-dipole interaction. The mechanism of excitation and infrared luminescence in NaYGeO4:Tm3+, Ho3+ phosphors has been proposed.
{"title":"Energy transfer mechanism in infrared-emitting NaYGeO4:Tm3+, Ho3+ phosphors","authors":"Anna A. Melentsova, Olga A. Lipina, Alexander Yu. Chufarov, Alexander P. Tyutyunnik, Vladimir G. Zubkov","doi":"10.1016/j.ceramint.2024.09.300","DOIUrl":"10.1016/j.ceramint.2024.09.300","url":null,"abstract":"<div><div>Two series of NaY<sub>0.85</sub>Tm<sub>0.15-x</sub>Ho<sub>x</sub>GeO<sub>4</sub> (x = 0.005–0.03) and NaY<sub>0.85-x</sub>Tm<sub>0.15</sub>Ho<sub>x</sub>GeO<sub>4</sub> (x = 0.0–0.055) phosphors have been prepared by the citrate technique. According to XRPD study, all the germanates crystallize in olivine structure and have an orthorhombic lattice, space group <em>Pnma</em>, Z = 4. The diffuse reflectance spectra have been measured and the optical band gap has been estimated. Under 808 nm laser diode excitation, the NaYGeO<sub>4</sub>:Tm<sup>3+</sup>, Ho<sup>3+</sup> samples exhibit luminescence in the range of 1640–2240 nm, which is caused by <sup>3</sup>F<sub>4</sub> → <sup>3</sup>H<sub>6</sub> transition in Tm<sup>3+</sup> and <sup>5</sup>I<sub>7</sub> → <sup>5</sup>I<sub>8</sub> transition in Ho<sup>3+</sup> ions. The highest intensity of holmium lines, while maintaining relatively high intensity of thulium lines, was observed for NaY<sub>0.82</sub>Tm<sub>0.15</sub>Ho<sub>0.03</sub>GeO<sub>4</sub>, NaY<sub>0.815</sub>Tm<sub>0.15</sub>Ho<sub>0.035</sub>GeO<sub>4</sub> samples with the Tm<sup>3+</sup>/Ho<sup>3+</sup> ratio close to 5/1. The luminescence decay kinetics has been studied and the rate of energy transfer from Tm<sup>3+</sup> to Ho<sup>3+</sup> ions has been calculated. The obtained results indicate an effective energy transfer accelerated by migration due to dipole-dipole interaction. The mechanism of excitation and infrared luminescence in NaYGeO<sub>4</sub>:Tm<sup>3+</sup>, Ho<sup>3+</sup> phosphors has been proposed.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49545-49551"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.330
Bowen Li , Chengyuan Li , Pengze Li , Zhiwen Zhang , Yunxuan Zhu , Bing Wang , Liyang Qin , Qianqiao Chen , Ye Song , Xufei Zhu
In order to investigate the effect of organic electrolytes on the photocurrent performance of TiO2 nanotubes, four kinds of fluoride containing electrolyte were prepared. This work focuses on the effect of electrolyte on the photocurrent response of TiO2 nanotubes. The results show that the electrolyte is an important influence on the photocurrent response. Appropriate proportion of polyethylene glycol (PEG) organic solvent can improve the performance of photocurrent response. The addition of excessive organic solvent will make TiO2 nanotubes lose the ability of photocurrent response. Suitable surface porosity is a necessary condition for the sample to have photocurrent response. Too low porosity hinders the photoelectric property. The reason for the better photoelectric properties of the sample prepared in 50 wt% PEG electrolyte is explained by the ionic current and electronic current theory. The results show that a more stable ratio of accumulated charge by ionic and electronic currents per unit area creates a more stable photocurrent response when the voltage is increased from 40 V to 60 V.
为了研究有机电解质对 TiO2 纳米管光电流性能的影响，制备了四种含氟电解质。本研究主要探讨了电解质对 TiO2 纳米管光电流响应的影响。结果表明，电解质对光电流响应有重要影响。适当比例的聚乙二醇（PEG）有机溶剂可以改善光电流响应性能。过量的有机溶剂会使 TiO2 纳米管失去光电流响应能力。合适的表面孔隙率是样品产生光电流响应的必要条件。过低的孔隙率会阻碍光电特性。离子电流和电子电流理论可以解释在 50 wt% PEG 电解质中制备的样品具有更好光电特性的原因。结果表明，当电压从 40 V 增加到 60 V 时，单位面积上离子电流和电子电流累积电荷的比例越稳定，光电流响应就越稳定。
{"title":"Morphology and photocurrent response of TiO2 nanotubes prepared in electrolytes containing different content of polyethylene glycol","authors":"Bowen Li , Chengyuan Li , Pengze Li , Zhiwen Zhang , Yunxuan Zhu , Bing Wang , Liyang Qin , Qianqiao Chen , Ye Song , Xufei Zhu","doi":"10.1016/j.ceramint.2024.09.330","DOIUrl":"10.1016/j.ceramint.2024.09.330","url":null,"abstract":"<div><div>In order to investigate the effect of organic electrolytes on the photocurrent performance of TiO<sub>2</sub> nanotubes, four kinds of fluoride containing electrolyte were prepared. This work focuses on the effect of electrolyte on the photocurrent response of TiO<sub>2</sub> nanotubes. The results show that the electrolyte is an important influence on the photocurrent response. Appropriate proportion of polyethylene glycol (PEG) organic solvent can improve the performance of photocurrent response. The addition of excessive organic solvent will make TiO<sub>2</sub> nanotubes lose the ability of photocurrent response. Suitable surface porosity is a necessary condition for the sample to have photocurrent response. Too low porosity hinders the photoelectric property. The reason for the better photoelectric properties of the sample prepared in 50 wt% PEG electrolyte is explained by the ionic current and electronic current theory. The results show that a more stable ratio of accumulated charge by ionic and electronic currents per unit area creates a more stable photocurrent response when the voltage is increased from 40 V to 60 V.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49862-49870"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.301
Yao Du , Zheng Chen , Yiliang Lu , Lanlan Yang , Cheng Wang , Shenglong Zhu , Fuhui Wang
Potassium silicate coatings cured by calcium hydrogen phosphate and modified by fillers of Ti and SiO2 powders were prepared on K447A alloy at 120 °C. The influences of Ti, SiO2 and both powders on the oxidation behavior of the coated specimens were investigated at 1000 °C for 100 h in static air by thermogravimetry, SEM, XRD and EPMA. The bare K447A alloy suffered severe oxidation at 1000 °C, and the TGO was found to be composited of an outer layer of mixtures of NiCr2O4, CoAl2O4 and rutile TiO2, and an inner α-Al2O3 layer. The potassium silicate coating without filler showed local damages where formation and rapid rupture of bubbles occurred and consequently the local substrate was oxidized. The SiO2 powder in the coatings is more capable of reducing O diffusion thru the coatings than the Ti powder, while the latter is more effective in getting rid of bubble rupture than the former. Thus, the coating modified by 10 wt% Ti and 20 wt% SiO2 showed the best protective performance.
在 K447A 合金上制备了由磷酸氢钙固化并由 Ti 和 SiO2 粉末填料改性的硅酸钾涂层，温度为 120 °C。通过热重仪、扫描电镜、XRD 和 EPMA，研究了 Ti、SiO2 和这两种粉末在 1000 °C 静态空气中 100 小时对涂层试样氧化行为的影响。裸露的 K447A 合金在 1000 ℃ 时发生了严重氧化，TGO 由外层的 NiCr2O4、CoAl2O4 和金红石 TiO2 混合物以及内层的 αAl2O3 层组成。没有填料的硅酸钾涂层出现局部损坏，气泡形成并迅速破裂，导致局部基底氧化。涂层中的二氧化硅粉末比钛粉末更能减少 O 在涂层中的扩散，而后者比前者更能有效地消除气泡破裂。因此，由 10 wt% Ti 和 20 wt% SiO2 改性的涂层显示出最佳的保护性能。
{"title":"Protection behavior of Ti-SiO2 modified potassium silicate coating on K447a alloy at 1000 °C","authors":"Yao Du , Zheng Chen , Yiliang Lu , Lanlan Yang , Cheng Wang , Shenglong Zhu , Fuhui Wang","doi":"10.1016/j.ceramint.2024.09.301","DOIUrl":"10.1016/j.ceramint.2024.09.301","url":null,"abstract":"<div><div>Potassium silicate coatings cured by calcium hydrogen phosphate and modified by fillers of Ti and SiO<sub>2</sub> powders were prepared on K447A alloy at 120 °C. The influences of Ti, SiO<sub>2</sub> and both powders on the oxidation behavior of the coated specimens were investigated at 1000 °C for 100 h in static air by thermogravimetry, SEM, XRD and EPMA. The bare K447A alloy suffered severe oxidation at 1000 °C, and the TGO was found to be composited of an outer layer of mixtures of NiCr<sub>2</sub>O<sub>4</sub>, CoAl<sub>2</sub>O<sub>4</sub> and rutile TiO<sub>2</sub>, and an inner α-Al<sub>2</sub>O<sub>3</sub> layer. The potassium silicate coating without filler showed local damages where formation and rapid rupture of bubbles occurred and consequently the local substrate was oxidized. The SiO<sub>2</sub> powder in the coatings is more capable of reducing O diffusion thru the coatings than the Ti powder, while the latter is more effective in getting rid of bubble rupture than the former. Thus, the coating modified by 10 wt% Ti and 20 wt% SiO<sub>2</sub> showed the best protective performance.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49552-49567"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.311
Ruyuan Wang, Chao Zhao, Haolong Liu, Jinbao Long, Xuan Luo, Minghan Sun, Ning Li
TiNi alloys with excellent mechanical properties and unique functional characteristics show substantial potential for producing engineered structural components and biomedical materials. However, the high reactivity of molten TiNi poses significant challenges when ceramic crucibles are used in vacuum induction melting, inevitably resulting in severe ingot contamination. In this study, we report an innovative method for producing high-purity, low-contamination TiNi ingots by using a ZrN/AlN composite ceramic crucible. Fundamentally, this ZrN/AlN composite crucible fabricated with vacuum pressureless sintering technology, is characterized by its high relative density (>95 %) and absence of cracks. The ZrN/AlN composites exhibit impressive properties, including excellent flexural strength, high thermal conductivity, and exceptional thermal shock resistance. Notably, during induction melting, the crucible surface forms a dense TiN barrier layer, thereby protecting the crucible substrate. Compared with traditional oxide refractories, the as-prepared ingots have a low interstitial atom content (Wt. (O, N) < 1000 ppm), demonstrating the superior corrosion resistance of the ZrN/AlN composite crucible. This work provides a comprehensive understanding of crucible-melt interaction mechanisms and a promising method for producing high-purity TiNi alloys.
钛镍合金具有优异的机械性能和独特的功能特性，在生产工程结构部件和生物医学材料方面具有巨大潜力。然而，当在真空感应熔炼中使用陶瓷坩埚时，熔融 TiNi 的高反应性带来了巨大挑战，不可避免地导致严重的铸锭污染。在本研究中，我们报告了一种使用 ZrN/AlN 复合陶瓷坩埚生产高纯度、低污染钛镍铸锭的创新方法。从根本上说，这种采用真空无压烧结技术制造的 ZrN/AlN 复合坩埚具有相对密度高（95%）和无裂纹的特点。ZrN/AlN 复合材料表现出令人印象深刻的特性，包括出色的抗弯强度、高导热性和优异的抗热震性。值得注意的是，在感应熔化过程中，坩埚表面会形成致密的 TiN 隔离层，从而保护坩埚基底。与传统的氧化物耐火材料相比，制备的铸锭具有较低的间隙原子含量（Wt. (O, N) < 1000 ppm），这表明 ZrN/AlN 复合坩埚具有优异的耐腐蚀性。这项工作为全面了解坩埚与熔体之间的相互作用机制以及生产高纯度钛镍合金提供了一种可行的方法。
{"title":"Chemical inertness and thermal shock resistance of ZrN/AlN composites for TiNi alloy induction melting","authors":"Ruyuan Wang, Chao Zhao, Haolong Liu, Jinbao Long, Xuan Luo, Minghan Sun, Ning Li","doi":"10.1016/j.ceramint.2024.09.311","DOIUrl":"10.1016/j.ceramint.2024.09.311","url":null,"abstract":"<div><div>TiNi alloys with excellent mechanical properties and unique functional characteristics show substantial potential for producing engineered structural components and biomedical materials. However, the high reactivity of molten TiNi poses significant challenges when ceramic crucibles are used in vacuum induction melting, inevitably resulting in severe ingot contamination. In this study, we report an innovative method for producing high-purity, low-contamination TiNi ingots by using a ZrN/AlN composite ceramic crucible. Fundamentally, this ZrN/AlN composite crucible fabricated with vacuum pressureless sintering technology, is characterized by its high relative density (>95 %) and absence of cracks. The ZrN/AlN composites exhibit impressive properties, including excellent flexural strength, high thermal conductivity, and exceptional thermal shock resistance. Notably, during induction melting, the crucible surface forms a dense TiN barrier layer, thereby protecting the crucible substrate. Compared with traditional oxide refractories, the as-prepared ingots have a low interstitial atom content (Wt. (O, N) < 1000 ppm), demonstrating the superior corrosion resistance of the ZrN/AlN composite crucible. This work provides a comprehensive understanding of crucible-melt interaction mechanisms and a promising method for producing high-purity TiNi alloys.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49667-49681"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.255
S. Taoussi , K. Hoummada , A. Lahmar , M. Naji , H. Bih , J. Alami , B. Manoun , A. El bouari , H. frielinghaus , P. Lazor , M.P.F. Graça , L. Bih
Advancing energy density, enabling lithium metal anodes, and ensuring unparalleled safety and operational reliability in lithium batteries hinge on advancing inorganic solid-state electrolytes. To overcome current impediments, we present an innovative approach that integrates glass-ceramics with a pioneering new Nasicon strategy involving molybdenum doping. In the conducted study, a series of 14Li2O-9Al2O3-38TiO2-(39-x)P2O5-xMoO3 glasses, denoted as LATPMox, along with their corresponding glass-ceramics (LATPMox-GC), have exhibited a promising characteristic as solid electrolytes. X-ray diffraction (XRD) analysis confirms the formation of the novel Mo-doped Nasicon phases in the glass-ceramics, as validated by Rietveld refinement. Examination of the crystallization kinetic behavior of the glasses reveals a three-dimensional nucleation process with spherical particle growth, featuring an activation energy of 165 kJ mol−1. Transmission Electron Microscopy TEM characterization aligns crystallization behavior with crystallite and distribution within the glass matrix, resulting in a compact and dense microstructure. The structural properties of the resultant phases are examined through FT-IR, Raman spectroscopy, and TEM-SEAD analysis. Vickers indentation tests were employed to assess the microscopic fracture toughness, and both the glass and glass-ceramics materials demonstrated favorable mechanical performance. Optical characterization using UV–visible absorption highlights the reduction of Mo6+ to Mo5+, likely occupying tetrahedral sites within the crystalline lattice. Impedance spectroscopy measurement showcases the effective promotion of ionic conductivity following Mo doping, reaching a total conductivity value of 5.50 × 10−5 Ω−1 cm−1 along with a high lithium transference number of 0.99 at room temperature for LATPMo2.6-GC glass-ceramic. This value is larger than that of many other glass-ceramics as well as that of the well-known lithium phosphorous oxy-nitride LiPON solid electrolyte whose ionic conductivity at RT is around 2 × 10−6 Ω−1 cm−1.
{"title":"Glass-ceramics and molybdenum doping synergistic approach for Nasicon-type solid-state electrolytes","authors":"S. Taoussi , K. Hoummada , A. Lahmar , M. Naji , H. Bih , J. Alami , B. Manoun , A. El bouari , H. frielinghaus , P. Lazor , M.P.F. Graça , L. Bih","doi":"10.1016/j.ceramint.2024.09.255","DOIUrl":"10.1016/j.ceramint.2024.09.255","url":null,"abstract":"<div><div>Advancing energy density, enabling lithium metal anodes, and ensuring unparalleled safety and operational reliability in lithium batteries hinge on advancing inorganic solid-state electrolytes. To overcome current impediments, we present an innovative approach that integrates glass-ceramics with a pioneering new Nasicon strategy involving molybdenum doping. In the conducted study, a series of 14Li<sub>2</sub>O-9Al<sub>2</sub>O<sub>3</sub>-38TiO<sub>2</sub>-(39-x)P<sub>2</sub>O<sub>5</sub>-xMoO<sub>3</sub> glasses, denoted as LATPMo<sub>x</sub>, along with their corresponding glass-ceramics (LATPMo<sub>x</sub>-GC), have exhibited a promising characteristic as solid electrolytes. X-ray diffraction (XRD) analysis confirms the formation of the novel Mo-doped Nasicon phases in the glass-ceramics, as validated by Rietveld refinement. Examination of the crystallization kinetic behavior of the glasses reveals a three-dimensional nucleation process with spherical particle growth, featuring an activation energy of 165 kJ mol<sup>−1</sup>. Transmission Electron Microscopy TEM characterization aligns crystallization behavior with crystallite and distribution within the glass matrix, resulting in a compact and dense microstructure. The structural properties of the resultant phases are examined through FT-IR, Raman spectroscopy, and TEM-SEAD analysis. Vickers indentation tests were employed to assess the microscopic fracture toughness, and both the glass and glass-ceramics materials demonstrated favorable mechanical performance. Optical characterization using UV–visible absorption highlights the reduction of Mo<sup>6+</sup> to Mo<sup>5+</sup>, likely occupying tetrahedral sites within the crystalline lattice. Impedance spectroscopy measurement showcases the effective promotion of ionic conductivity following Mo doping, reaching a total conductivity value of 5.50 × 10<sup>−5</sup> Ω<sup>−1</sup> cm<sup>−1</sup> along with a high lithium transference number of 0.99 at room temperature for LATPMo<sub>2.6</sub>-GC glass-ceramic. This value is larger than that of many other glass-ceramics as well as that of the well-known lithium phosphorous oxy-nitride LiPON solid electrolyte whose ionic conductivity at RT is around 2 × 10<sup>−6</sup> Ω<sup>−1</sup> cm<sup>−1</sup>.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49134-49149"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.303
Lu Yin , Xinyu Li , Duoduo Xiao , Sijia He , Ying Zhao , Qiangxiang Peng , Qiong Yang , Yunya Liu , Chuanbin Wang
Doped Hf0.5Zr0.5O2 materials have drawn increasing attention due to the excellent ferroelectric properties, but the relevant research is just in the preliminary stage and the reported doped systems are rare. In this work, Ca doped Hf0.5Zr0.5O2 (Ca:HZO) ferroelectric films were successfully fabricated via chemical solution deposition and investigated for the first time. It is observed that Ca doping induces a phase transformation from monoclinic to orthorhombic/tetragonal and then to monoclinic/tetragonal. The highest orthorhombic phase fraction is achieved in 2.5 mol% Ca doped HZO film, contributing to the optimum ferroelectric property with the largest remnant polarization of 14.00 μC/cm2 after 105 cycles. Additionally, the leakage current density is observed to decrease with increasing Ca content, which is mainly associated with the changes of grain size and surface roughness. As a result, the endurance is significantly improved in the Ca doped films, and an excellent endurance of 1010 cycles is achieved in the 2.5 mol% Ca doped film. These results suggest that Ca doping can enhance the ferroelectric and endurance properties of HZO films by optimizing the phase and morphological structure.
掺杂 Hf0.5Zr0.5O2 材料因其优异的铁电特性而受到越来越多的关注，但目前相关研究还处于起步阶段，报道的掺杂体系还很少。本研究首次通过化学溶液沉积法成功制备并研究了掺杂 Ca 的 Hf0.5Zr0.5O2 （Ca:HZO）铁电薄膜。研究发现，钙掺杂诱导了从单斜到正方/四方再到单斜/四方的相变。在掺杂 2.5 mol% Ca 的 HZO 薄膜中，正方晶相的比例最高，从而获得了最佳的铁电特性，105 次循环后的最大残余极化为 14.00 μC/cm2。此外，还观察到漏电流密度随 Ca 含量的增加而降低，这主要与晶粒尺寸和表面粗糙度的变化有关。因此，掺 Ca 薄膜的耐久性显著提高，掺 Ca 2.5 mol% 的薄膜达到了 1010 次循环的优异耐久性。这些结果表明，通过优化相结构和形态结构，掺杂 Ca 可以增强 HZO 薄膜的铁电性和耐久性。
{"title":"Improved ferroelectricity and endurance in Ca doped Hf0.5Zr0.5O2 films","authors":"Lu Yin , Xinyu Li , Duoduo Xiao , Sijia He , Ying Zhao , Qiangxiang Peng , Qiong Yang , Yunya Liu , Chuanbin Wang","doi":"10.1016/j.ceramint.2024.09.303","DOIUrl":"10.1016/j.ceramint.2024.09.303","url":null,"abstract":"<div><div>Doped Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> materials have drawn increasing attention due to the excellent ferroelectric properties, but the relevant research is just in the preliminary stage and the reported doped systems are rare. In this work, Ca doped Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub> (Ca:HZO) ferroelectric films were successfully fabricated via chemical solution deposition and investigated for the first time. It is observed that Ca doping induces a phase transformation from monoclinic to orthorhombic/tetragonal and then to monoclinic/tetragonal. The highest orthorhombic phase fraction is achieved in 2.5 mol% Ca doped HZO film, contributing to the optimum ferroelectric property with the largest remnant polarization of 14.00 μC/cm<sup>2</sup> after 10<sup>5</sup> cycles. Additionally, the leakage current density is observed to decrease with increasing Ca content, which is mainly associated with the changes of grain size and surface roughness. As a result, the endurance is significantly improved in the Ca doped films, and an excellent endurance of 10<sup>10</sup> cycles is achieved in the 2.5 mol% Ca doped film. These results suggest that Ca doping can enhance the ferroelectric and endurance properties of HZO films by optimizing the phase and morphological structure.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49577-49586"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.316
Jiyuan Cui , Hiroki Saito , Kazuhisa Sato , Yuji Ichikawa , Kazuhiro Ogawa , Makoto Nakashima , Atsushi Suzuki , Fumio Sato
The gradual transition of hydrogen as a fuel for land-based gas turbines has resulted in direct changes to the combustion environment. The inadequate combustion of hydrogen fuel can lead to a transition from an oxidizing environment to a partially reducing environment, and further introduces a new potential failure mode for existing thermal barrier coating materials. In this study, tests were conducted on thermal barrier coating samples at 1000 °C in Ar + 5 % O2 and Ar + 5 % H2 environments, in addition to samples subjected to heat-treatment in pure argon and air environments to provide a comparison against low oxygen partial pressure and conventional failure modes. The results demonstrated that the degree of sintering of the top coat decreased gradually with a decreasing oxygen partial pressure, and was significantly inhibited in a reducing environment. Faster cooling rates led to the expansion of vertical cracks in the top coat toward the interface, which was accompanied by the generation of numerous transverse cracks in the reducing environment. In contrast, the structure of the top coat remained intact in the other three environments. Furthermore, effective methods for improving the coating durability in reducing environments are discussed. This study therefore contributes to a comprehensive understanding of the failure behavior of thermal barrier coatings in reducing environments, providing new insights into enhancing the stability under such conditions.
氢作为陆基燃气轮机燃料的逐步过渡直接改变了燃烧环境。氢燃料燃烧不充分会导致从氧化环境过渡到部分还原环境，并进一步为现有隔热涂层材料带来新的潜在失效模式。在这项研究中，除了在纯氩气和空气环境中进行热处理的样品外，还在 1000 °C 的 Ar + 5 % O2 和 Ar + 5 % H2 环境中对隔热涂层样品进行了测试，以便对低氧分压和传统失效模式进行比较。结果表明，面层的烧结程度随着氧分压的降低而逐渐减弱，在还原环境中明显受到抑制。较快的冷却速度导致表层垂直裂纹向界面扩展，同时在还原环境中产生大量横向裂纹。相比之下，面层结构在其他三种环境中保持完好。此外，还讨论了在还原环境中提高涂层耐久性的有效方法。因此，这项研究有助于全面了解热障涂层在还原环境中的失效行为，为提高涂层在这种条件下的稳定性提供了新的见解。
{"title":"Degradation behavior of yttria-stabilized zirconia in thermal barrier coatings under reducing environments after short-term heat treatment","authors":"Jiyuan Cui , Hiroki Saito , Kazuhisa Sato , Yuji Ichikawa , Kazuhiro Ogawa , Makoto Nakashima , Atsushi Suzuki , Fumio Sato","doi":"10.1016/j.ceramint.2024.09.316","DOIUrl":"10.1016/j.ceramint.2024.09.316","url":null,"abstract":"<div><div>The gradual transition of hydrogen as a fuel for land-based gas turbines has resulted in direct changes to the combustion environment. The inadequate combustion of hydrogen fuel can lead to a transition from an oxidizing environment to a partially reducing environment, and further introduces a new potential failure mode for existing thermal barrier coating materials. In this study, tests were conducted on thermal barrier coating samples at 1000 °C in Ar + 5 % O<sub>2</sub> and Ar + 5 % H<sub>2</sub> environments, in addition to samples subjected to heat-treatment in pure argon and air environments to provide a comparison against low oxygen partial pressure and conventional failure modes. The results demonstrated that the degree of sintering of the top coat decreased gradually with a decreasing oxygen partial pressure, and was significantly inhibited in a reducing environment. Faster cooling rates led to the expansion of vertical cracks in the top coat toward the interface, which was accompanied by the generation of numerous transverse cracks in the reducing environment. In contrast, the structure of the top coat remained intact in the other three environments. Furthermore, effective methods for improving the coating durability in reducing environments are discussed. This study therefore contributes to a comprehensive understanding of the failure behavior of thermal barrier coatings in reducing environments, providing new insights into enhancing the stability under such conditions.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49724-49731"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.ceramint.2024.09.320
Yanli Ye , Zijun He , Zheng Qi , Wenkang Ye , Junlin Xie
Hexagonal boron nitride (h-BN) ceramics exhibit exceptional thermal conductivity, yet integrating their anisotropic thermal properties into bulk ceramics remains challenging. This study investigates the impact of bimodal particle size distribution on the structure, thermal and mechanical properties of h-BN ceramics. Through DEM simulations and hot-pressing techniques, we demonstrate that incorporating large particles into fine ones significantly enhances the packing density, structural anisotropy and thermal properties of h-BN ceramics. The resulting high-purity h-BN ceramic prepared with 10 vol% large particles (10LBN) exhibits an Index of Orientation Preference (IOP) of −2780.57, surpassing that of ceramics without large particles (0LBN) at −1168.61. By regulating the structure, 10LBN h-BN ceramic show a notable increase of the in-plane thermal conductivity from 81.78 for 0LBN ceramics to 153.20 W/(m·K), along with a flexural strength of 58.21 MPa. Additionally, structural characterization and performance testing show that, compared to adding sintering additives, incorporating large plate-like h-BN particles offers greater benefits in optimizing the orientation structure and thermal conductivity of h-BN ceramics. These findings offer new insights for powder compaction using dual-sized plate-like particles and into the sintering of h-BN ceramics with tailored structural and thermal properties.
{"title":"Optimizing structural anisotropy and thermal properties of hexagonal boron nitride ceramics through bimodal particle size distribution","authors":"Yanli Ye , Zijun He , Zheng Qi , Wenkang Ye , Junlin Xie","doi":"10.1016/j.ceramint.2024.09.320","DOIUrl":"10.1016/j.ceramint.2024.09.320","url":null,"abstract":"<div><div>Hexagonal boron nitride (h-BN) ceramics exhibit exceptional thermal conductivity, yet integrating their anisotropic thermal properties into bulk ceramics remains challenging. This study investigates the impact of bimodal particle size distribution on the structure, thermal and mechanical properties of h-BN ceramics. Through DEM simulations and hot-pressing techniques, we demonstrate that incorporating large particles into fine ones significantly enhances the packing density, structural anisotropy and thermal properties of h-BN ceramics. The resulting high-purity h-BN ceramic prepared with 10 vol% large particles (10LBN) exhibits an Index of Orientation Preference (IOP) of −2780.57, surpassing that of ceramics without large particles (0LBN) at −1168.61. By regulating the structure, 10LBN h-BN ceramic show a notable increase of the in-plane thermal conductivity from 81.78 for 0LBN ceramics to 153.20 W/(m·K), along with a flexural strength of 58.21 MPa. Additionally, structural characterization and performance testing show that, compared to adding sintering additives, incorporating large plate-like h-BN particles offers greater benefits in optimizing the orientation structure and thermal conductivity of h-BN ceramics. These findings offer new insights for powder compaction using dual-sized plate-like particles and into the sintering of h-BN ceramics with tailored structural and thermal properties.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 49770-49781"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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