Ruddlesden-Popper oxide Sr2Mn0.7Sn0.3O4 was synthesized by solid state method by calcining at different temperatures between 1200 and 1500?C. The phase evolution during thermal treatments was investigated and it was shown that the powder calcined at 1500?C and ceramics sintered at 1500?C have single phase structure. Rietveld refinement of the XRD data confirmed tetragonal crystal structure having a = b = 3.9425 ? and c = 12.1230? lattice parameters and I4/mmm space group symmetry. Permittivity (?), impedance (Z*), dissipation factor (tan ?) and AC conductivity (?AC) of the samples were studied in the frequency range 1 kHz-2MHz and temperature range 60-600?C. An equivalent circuit comprising two parallel R-L elements and one constant phase element (CPE) model fitted the impedance data very well. Components of the equivalent circuit were correlated with compositional micro inhomogeneities in the sintered sample. Resonance-like feature observed in the dissipation factor at a particular temperature is attributed to the cancellation of capacitive and inductive reactants. Negative permittivity and loss of the sintered sample were compared with other ceramic oxides showing negative permittivity.
{"title":"Study of phase evolution and dielectric properties of Sr2Mn0.7Sn0.3O4","authors":"G. Nirala, S. Upadhyay","doi":"10.2298/pac2302181n","DOIUrl":"https://doi.org/10.2298/pac2302181n","url":null,"abstract":"Ruddlesden-Popper oxide Sr2Mn0.7Sn0.3O4 was synthesized by solid state method by calcining at different temperatures between 1200 and 1500?C. The phase evolution during thermal treatments was investigated and it was shown that the powder calcined at 1500?C and ceramics sintered at 1500?C have single phase structure. Rietveld refinement of the XRD data confirmed tetragonal crystal structure having a = b = 3.9425 ? and c = 12.1230? lattice parameters and I4/mmm space group symmetry. Permittivity (?), impedance (Z*), dissipation factor (tan ?) and AC conductivity (?AC) of the samples were studied in the frequency range 1 kHz-2MHz and temperature range 60-600?C. An equivalent circuit comprising two parallel R-L elements and one constant phase element (CPE) model fitted the impedance data very well. Components of the equivalent circuit were correlated with compositional micro inhomogeneities in the sintered sample. Resonance-like feature observed in the dissipation factor at a particular temperature is attributed to the cancellation of capacitive and inductive reactants. Negative permittivity and loss of the sintered sample were compared with other ceramic oxides showing negative permittivity.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68583834","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}
Lu-doped SrBi2Ta2O9 (SrBi2-xLuxTa2O9 where x = 0, 0.025, 0.05, 0.75 and 0.1) powders were synthesized by combination of molten salt method and solid-state route. FTIR, Raman and XRD techniques were performed to follow the transformation of reactants into the desired products. Characterization of all samples shows pure and single-phase orthorhombic structured materials obtained with plate-like morphology that is composed of fine and coarse-grained particles. The prepared powders were pressed and sintered at different temperatures up to 1200?C. Microstructure of the sintered samples is also likely to be affected by doping. The first study of dielectric measurements describes the effect of the application of DC bias, at roomtemperature, on the undoped and Lu-doped ceramics and shows that there is little or no effect of DC bias. The sample SrBi1.95Lu0.05Ta2O9 had maximal dielectric constant (??) and minimal dielectric loss (tan?). In the second part of this work, the temperature dependence of ?? and tan_ was considered. It was concluded that Lu-doping not only reduces the Curie temperature, but also brings a diffused phase transition, showing a crossover between displacive and diffusive behaviour.
采用熔盐法和固态法相结合的方法合成了掺镧SrBi2Ta2O9 (SrBi2-xLuxTa2O9, x = 0、0.025、0.05、0.75和0.1)粉末。利用红外光谱(FTIR)、拉曼光谱(Raman)和x射线衍射(XRD)技术跟踪了反应物转化为所需产物的过程。所有样品的表征显示获得的纯单相正交结构材料具有板状形貌，由细颗粒和粗颗粒组成。制备的粉末在不同温度下进行压制和烧结，温度最高可达1200℃。烧结样品的微观结构也可能受到掺杂的影响。第一个介电测量研究描述了直流偏置在室温下对未掺杂和掺镧陶瓷的影响，并表明直流偏置的影响很小或没有影响。样品SrBi1.95Lu0.05Ta2O9具有最大介电常数(??)和最小介电损耗(??)。在本工作的第二部分，研究了??tan_被考虑过。结果表明，镧的掺杂不仅降低了居里温度，而且导致了扩散相变，表现出位移和扩散行为的交叉。
{"title":"Structure and dielectric properties of Lu-doped SrBi2Ta2O9 synthesized by the molten salt method","authors":"Mohamed Afqir, Didier Fasquelle, Amina Tachafine, Yingzhi Meng, Mohamed Elaatmani, Abdelouahad Zegzouti, Abdelhamid Oufakir, Mohamed Daoud","doi":"10.2298/pac2303256a","DOIUrl":"https://doi.org/10.2298/pac2303256a","url":null,"abstract":"Lu-doped SrBi2Ta2O9 (SrBi2-xLuxTa2O9 where x = 0, 0.025, 0.05, 0.75 and 0.1) powders were synthesized by combination of molten salt method and solid-state route. FTIR, Raman and XRD techniques were performed to follow the transformation of reactants into the desired products. Characterization of all samples shows pure and single-phase orthorhombic structured materials obtained with plate-like morphology that is composed of fine and coarse-grained particles. The prepared powders were pressed and sintered at different temperatures up to 1200?C. Microstructure of the sintered samples is also likely to be affected by doping. The first study of dielectric measurements describes the effect of the application of DC bias, at roomtemperature, on the undoped and Lu-doped ceramics and shows that there is little or no effect of DC bias. The sample SrBi1.95Lu0.05Ta2O9 had maximal dielectric constant (??) and minimal dielectric loss (tan?). In the second part of this work, the temperature dependence of ?? and tan_ was considered. It was concluded that Lu-doping not only reduces the Curie temperature, but also brings a diffused phase transition, showing a crossover between displacive and diffusive behaviour.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135263534","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}
Lithium-doped Li0.66La1.12(Ti0.2Zr0.2Hf0.2Sn0.2Nb0.2)2O7 (LLTNO), Li0.66La1.12(Ti0.2Zr0.2Hf0.2Sn0.2Ta0.2)2O7 (LLTTO) high-entropy pyrochlore and Li0.5Sr0.5(Ti0.2Zr0.2Hf0.2Sn0.2Ta0.2)O3 (LSTTO), Li0.5Ba0.5(Ti0.2Zr0.2Hf0.2Sn0.2Nb0.2)O3 (LBTNO) high-entropy perovskite ceramics were synthesized by solid state reaction method and sintered. Crystal structure, microstructure and electrical properties of these high entropy ceramics were studied. The LLTNO and LLTTO pellets sintered at 1300 ?C present a pyrochlore structure, while LSTTO and LBTNO pellets sintered at 1350 ?C present a perovskite structure. The LBTNO ceramics has a total conductivity of 1.25 ? 10?7 S?cm?1 at room temperature while the LSTTO sample exhibits the highest conductivity of 2.11 ? 10?7 S?cm?1 among all samples. Both LSTTO and LBTNO ceramics present negligible electronic conductivity. Relative densities of the LLTNO, LLTTO, LSTTO and LBTNO ceramics were 82, 88, 86 and 87%TD, respectively, which is the reason for low conductivity of these high entropy ceramics. The activation energies of the LSTTO and LBTNO samples were 0.39 and 0.38 eV, respectively, which is close to the traditional Li+-type conducting solid electrolytes.
{"title":"Processing and electrical conductivity property of lithium-doped high-entropy pyrochlore and perovskite ceramics","authors":"Yazhou Kong, Shihang Hu, Chengcheng Cai, Zexiong Wang, Shuai Zhang","doi":"10.2298/pac2303264k","DOIUrl":"https://doi.org/10.2298/pac2303264k","url":null,"abstract":"Lithium-doped Li0.66La1.12(Ti0.2Zr0.2Hf0.2Sn0.2Nb0.2)2O7 (LLTNO), Li0.66La1.12(Ti0.2Zr0.2Hf0.2Sn0.2Ta0.2)2O7 (LLTTO) high-entropy pyrochlore and Li0.5Sr0.5(Ti0.2Zr0.2Hf0.2Sn0.2Ta0.2)O3 (LSTTO), Li0.5Ba0.5(Ti0.2Zr0.2Hf0.2Sn0.2Nb0.2)O3 (LBTNO) high-entropy perovskite ceramics were synthesized by solid state reaction method and sintered. Crystal structure, microstructure and electrical properties of these high entropy ceramics were studied. The LLTNO and LLTTO pellets sintered at 1300 ?C present a pyrochlore structure, while LSTTO and LBTNO pellets sintered at 1350 ?C present a perovskite structure. The LBTNO ceramics has a total conductivity of 1.25 ? 10?7 S?cm?1 at room temperature while the LSTTO sample exhibits the highest conductivity of 2.11 ? 10?7 S?cm?1 among all samples. Both LSTTO and LBTNO ceramics present negligible electronic conductivity. Relative densities of the LLTNO, LLTTO, LSTTO and LBTNO ceramics were 82, 88, 86 and 87%TD, respectively, which is the reason for low conductivity of these high entropy ceramics. The activation energies of the LSTTO and LBTNO samples were 0.39 and 0.38 eV, respectively, which is close to the traditional Li+-type conducting solid electrolytes.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135263539","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}
Continuous silicon carbide fibre toughened silicon carbide composites (SiCf/SiC) are highly promising materials for nuclear reactor applications due to their low chemical activity, low density, low coefficient of thermal expansion, high energy conversion rate and good high temperature strength. However, the thermal conductivity requirements of nuclear reactors are difficult to meet in conventional SiCf/SiC composites. To improve the thermal conductivity of SiCf/SiC composites, many approaches to enhance the thermal conductivity of SiCf/SiC composites under nuclear reactor applications were firstly introduced. Further, the worldwide research process in this field has been reviewed. Finally, further development of the thermal conductivity research was discussed and prospected.
{"title":"Review on thermal conductivity of SiCf/SiC composites for nuclear applications","authors":"Weina Guo, Yantao Gao","doi":"10.2298/pac2303203g","DOIUrl":"https://doi.org/10.2298/pac2303203g","url":null,"abstract":"Continuous silicon carbide fibre toughened silicon carbide composites (SiCf/SiC) are highly promising materials for nuclear reactor applications due to their low chemical activity, low density, low coefficient of thermal expansion, high energy conversion rate and good high temperature strength. However, the thermal conductivity requirements of nuclear reactors are difficult to meet in conventional SiCf/SiC composites. To improve the thermal conductivity of SiCf/SiC composites, many approaches to enhance the thermal conductivity of SiCf/SiC composites under nuclear reactor applications were firstly introduced. Further, the worldwide research process in this field has been reviewed. Finally, further development of the thermal conductivity research was discussed and prospected.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"157 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135312430","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}
Eduardo Hernández-Silva, F. Vázquez-Hernández, S. Mendoza-Acevedo, M. Pérez-González, S. Tomás-Velázquez, P. Rodríguez-Fragoso, J. Mendoza-Álvarez, Pedro Luna-Arias
Chemical synthesis is one of the most employed methods to obtain crystalline hydroxyapatite nanoparticles. It is feasible to vary the synthesis conditions and study their effects on nanoparticle structure. In this work, hydroxyapatite nanoparticles were synthesised by a modified heat-treated precipitation method and varying stirring rate of the solution during the nucleation process. The main goal was to reduce the particle size without affecting the crystallinity degree of the synthesized material what is important for several use cases, such as biomedical applications. The produced materials were characterized by X-ray diffraction, Fourier transformed infrared spectroscopy, ?-Raman spectroscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy. The nanoparticle?s size decreased by increasing the stirring rate during the nucleation step, showing that the employed synthesis method is efficient for obtaining hydroxyapatite nanoparticles of variable sizes without affecting the crystallinity degree.
{"title":"Effect of stirring rate on the size of hydroxyapatite nanoparticles synthesized by a modified heat-treated precipitation method","authors":"Eduardo Hernández-Silva, F. Vázquez-Hernández, S. Mendoza-Acevedo, M. Pérez-González, S. Tomás-Velázquez, P. Rodríguez-Fragoso, J. Mendoza-Álvarez, Pedro Luna-Arias","doi":"10.2298/pac2302133h","DOIUrl":"https://doi.org/10.2298/pac2302133h","url":null,"abstract":"Chemical synthesis is one of the most employed methods to obtain crystalline hydroxyapatite nanoparticles. It is feasible to vary the synthesis conditions and study their effects on nanoparticle structure. In this work, hydroxyapatite nanoparticles were synthesised by a modified heat-treated precipitation method and varying stirring rate of the solution during the nucleation process. The main goal was to reduce the particle size without affecting the crystallinity degree of the synthesized material what is important for several use cases, such as biomedical applications. The produced materials were characterized by X-ray diffraction, Fourier transformed infrared spectroscopy, ?-Raman spectroscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy. The nanoparticle?s size decreased by increasing the stirring rate during the nucleation step, showing that the employed synthesis method is efficient for obtaining hydroxyapatite nanoparticles of variable sizes without affecting the crystallinity degree.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68583066","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}
Hind Neelamkodan, U. Megha, Puzhakkara Manathanath Binitha
The nanoflowers and nanoblocks of Fe-doped ZnO (i.e. ZnO doped with 0, 1, 2, 3, 4 and 5% Fe) were synthesised by co-precipitation technique. XRD analysis showed that the samples have wurtzite structure containing mostly Fe3+ in the samples with 1% Fe and a mixture of Fe3+ and Fe2+ in the samples with higher amount of dopant. Morphology transformations from nanoflowers to nanoblocks, then into a combination of nanoflowers and nanoblocks were observed. The UV analysis identified the presence of multi-absorption regions in the doped samples. Due to the elevated Fe2+ concentration, the band gap of the 5% doped nanoblocks expanded and behaved irregularly. The room temperature photoluminescence characteristics of the Fe-doped ZnO nanostructures were determined. It was found that, in addition to the detected peaks in the yellow and red regions, the sample doped with 1%Fe shows two peaks in the blue region which could be interesting for multifunctional applications in the field of optoelectronics.
{"title":"Multi peak emission and morphological evolution of Fe-doped ZnOs nanoflowers","authors":"Hind Neelamkodan, U. Megha, Puzhakkara Manathanath Binitha","doi":"10.2298/pac2302149n","DOIUrl":"https://doi.org/10.2298/pac2302149n","url":null,"abstract":"The nanoflowers and nanoblocks of Fe-doped ZnO (i.e. ZnO doped with 0, 1, 2, 3, 4 and 5% Fe) were synthesised by co-precipitation technique. XRD analysis showed that the samples have wurtzite structure containing mostly Fe3+ in the samples with 1% Fe and a mixture of Fe3+ and Fe2+ in the samples with higher amount of dopant. Morphology transformations from nanoflowers to nanoblocks, then into a combination of nanoflowers and nanoblocks were observed. The UV analysis identified the presence of multi-absorption regions in the doped samples. Due to the elevated Fe2+ concentration, the band gap of the 5% doped nanoblocks expanded and behaved irregularly. The room temperature photoluminescence characteristics of the Fe-doped ZnO nanostructures were determined. It was found that, in addition to the detected peaks in the yellow and red regions, the sample doped with 1%Fe shows two peaks in the blue region which could be interesting for multifunctional applications in the field of optoelectronics.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68583269","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}
The copper doped ZnO (CuxZn1-xO, where x = 0, 0.01, 0.02, 0.04, 0.05) nanoflowers were produced by using co-precipitation process. Hexagonal wurtzite nanocrystalline phase of both pure and Cu-doped samples was confirmed by X-ray diffraction analysis. Field emission scanning electron microscopy results confirmed the emergence of fully dispersed nanoflower like morphologies in the Cu-doped ZnO and uniform dispersion of particles. Band gap energies of the prepared samples were calculated using the Tauc?s plot. All of the generated samples? room temperature photoluminescent spectra show two emission peaks, one excitonic peak in the UV region and another broad defect level peak in the visible area. The yellow and green luminescence characteristics of both pure and doped samples were analysed via the PL spectra in visible light region, making them appropriate for optoelectronic applications. The antibacterial potential of the produced nanostructures against the bacterial strains of Enterococcus Faecalis (gram positive) and Pseudomonas Aeruginosa (gram negative) were assessed. When compared to the pure ZnO nanostructures, the doped samples exhibit enhanced antibacterial activity. For the samples with 5 at.%Cu, the greatest zone of inhibition against Pseudomonas Aeruginosa was noted to be 25mm. For the samples doped with 5 at.% Cu, the largest zone of inhibition against Enterococcus Faecalis was 21mm. The findings indicate that the obtained samples have higher antibacterial potential against gram negative than gram positive bacteria. The prepared doped ZnO nanoflowers were therefore recommended as excellent green nanophosphors for the production of white LEDs and effective nanoantibiotics against gram-negative bacteria.
采用共沉淀法制备了铜掺杂ZnO (CuxZn1-xO, x = 0,0.01, 0.02, 0.04, 0.05)纳米花。通过x射线衍射分析证实了纯铜和掺铜样品的六方纤锌矿纳米晶相。场发射扫描电镜结果证实了cu掺杂ZnO中出现了完全分散的纳米花状形貌和均匀分散的颗粒。利用Tauc?年代的阴谋。所有生成的样本?室温光致发光光谱显示两个发射峰，一个激子峰在紫外区，另一个宽缺陷能级峰在可见光区。通过可见光区PL光谱分析了纯样品和掺杂样品的黄色和绿色发光特性，使其适合光电应用。对制备的纳米结构对粪肠球菌(革兰氏阳性)和铜绿假单胞菌(革兰氏阴性)的抗菌潜力进行了评估。与纯ZnO纳米结构相比，掺杂样品的抗菌活性增强。对于含有5个at的样品。%Cu，对铜绿假单胞菌的最大抑制区为25mm。对于掺杂5at的样品。% Cu，对粪肠球菌的最大抑制区为21mm。结果表明，所得样品对革兰氏阴性菌的抑菌潜力高于革兰氏阳性菌。因此，所制备的掺杂ZnO纳米花被推荐为生产白光led和有效的抗革兰氏阴性菌纳米抗生素的优秀绿色纳米荧光粉。
{"title":"Enhanced green luminescence properties of cu doped ZnO nano-flowers and their improved antibacterial activities","authors":"Hind Neelamkodan, U. Megha, Manathanath Binitha","doi":"10.2298/pac2301081n","DOIUrl":"https://doi.org/10.2298/pac2301081n","url":null,"abstract":"The copper doped ZnO (CuxZn1-xO, where x = 0, 0.01, 0.02, 0.04, 0.05) nanoflowers were produced by using co-precipitation process. Hexagonal wurtzite nanocrystalline phase of both pure and Cu-doped samples was confirmed by X-ray diffraction analysis. Field emission scanning electron microscopy results confirmed the emergence of fully dispersed nanoflower like morphologies in the Cu-doped ZnO and uniform dispersion of particles. Band gap energies of the prepared samples were calculated using the Tauc?s plot. All of the generated samples? room temperature photoluminescent spectra show two emission peaks, one excitonic peak in the UV region and another broad defect level peak in the visible area. The yellow and green luminescence characteristics of both pure and doped samples were analysed via the PL spectra in visible light region, making them appropriate for optoelectronic applications. The antibacterial potential of the produced nanostructures against the bacterial strains of Enterococcus Faecalis (gram positive) and Pseudomonas Aeruginosa (gram negative) were assessed. When compared to the pure ZnO nanostructures, the doped samples exhibit enhanced antibacterial activity. For the samples with 5 at.%Cu, the greatest zone of inhibition against Pseudomonas Aeruginosa was noted to be 25mm. For the samples doped with 5 at.% Cu, the largest zone of inhibition against Enterococcus Faecalis was 21mm. The findings indicate that the obtained samples have higher antibacterial potential against gram negative than gram positive bacteria. The prepared doped ZnO nanoflowers were therefore recommended as excellent green nanophosphors for the production of white LEDs and effective nanoantibiotics against gram-negative bacteria.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582864","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}
Commercial La0.6Sr0.4Co0.2Fe0.8O3-? powder was used for preparation of corresponding perovskite films on commercial Crofer 22 APU high chromium steel by pulsed laser deposition. The obtained films PLD1 and PLD2 with a thickness of 1.1 and 0.35 ?m, respectively, were dense and homogeneous, with good adhesion to the polished surface. Oxidation studies of the samples were carried out in air at 800?C for 200h. The calculated parabolic rate constant kp after isothermal oxidation for the PLD1 sample was 4.10 ? 10?14 g2cm?4s?1 and was approximately four times lower than the oxidation rate determined for the PLD2 sample. As a result of the oxidation process, in both cases, a thin oxide layer of chromia and Mn1.5Cr1.5O4 spinel was formed on the steel/film interface. In addition, small amounts of manganese-chromium spinel crystals were observed on the films? surfaces. Values of the specific electrical resistance at 800 ?C after 100 h of the experiment were 0.06 and 0.038W?cm2 for PLD1 and PLD2, respectively. The results indicate that the applied coatings meet the criteria set upon protective-conductive layers for interconnect materials, for the IT-SOFCs (intermediate-temperature solid oxide fuel cells) applications.
{"title":"Physicochemical properties of the Crofer 22 APU steel with La0.6Sr0.4Co0.2Fe0.8O3-δ protective-conductive coatings prepared by pulsed laser deposition","authors":"Ewa Durda, Andrzej Kruk","doi":"10.2298/pac2303301d","DOIUrl":"https://doi.org/10.2298/pac2303301d","url":null,"abstract":"Commercial La0.6Sr0.4Co0.2Fe0.8O3-? powder was used for preparation of corresponding perovskite films on commercial Crofer 22 APU high chromium steel by pulsed laser deposition. The obtained films PLD1 and PLD2 with a thickness of 1.1 and 0.35 ?m, respectively, were dense and homogeneous, with good adhesion to the polished surface. Oxidation studies of the samples were carried out in air at 800?C for 200h. The calculated parabolic rate constant kp after isothermal oxidation for the PLD1 sample was 4.10 ? 10?14 g2cm?4s?1 and was approximately four times lower than the oxidation rate determined for the PLD2 sample. As a result of the oxidation process, in both cases, a thin oxide layer of chromia and Mn1.5Cr1.5O4 spinel was formed on the steel/film interface. In addition, small amounts of manganese-chromium spinel crystals were observed on the films? surfaces. Values of the specific electrical resistance at 800 ?C after 100 h of the experiment were 0.06 and 0.038W?cm2 for PLD1 and PLD2, respectively. The results indicate that the applied coatings meet the criteria set upon protective-conductive layers for interconnect materials, for the IT-SOFCs (intermediate-temperature solid oxide fuel cells) applications.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135270025","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}
Experimental evidence shows that natural bone is piezoelectric, and bioelectric phenomena in natural bone play an essential role in bone development and bone defect repair. Piezoelectric ceramics can deform with physiological movements and consequently deliver electrical stimulation to cells or damaged tissue without the need for an external power source. They exhibit piezoelectricity and good biological properties similar to those of natural bone and have shown great potential in bone tissue engineering. This study aims to present an overview of the relationship between electrical stimulation and bone repair as well as the principle of the piezoelectric effect, emphasizing the material characteristics, research progress and application of piezoelectric ceramics in bone tissue regeneration. The limitations of piezoelectric ceramics in promoting osteogenesis by electrical stimulation were also analysed. Overall, this review comprehensively emphasized the essential characteristics of piezoelectric ceramics and pointed out the new direction for the future development of piezoelectric ceramics.
{"title":"Lead-free piezoelectric ceramics - an electroactive material that provides electrical stimulation cues for bone regeneration","authors":"Zhengyang Jin, Bingheng Lu, Yan Xu, Xujing Zhang","doi":"10.2298/pac2303214j","DOIUrl":"https://doi.org/10.2298/pac2303214j","url":null,"abstract":"Experimental evidence shows that natural bone is piezoelectric, and bioelectric phenomena in natural bone play an essential role in bone development and bone defect repair. Piezoelectric ceramics can deform with physiological movements and consequently deliver electrical stimulation to cells or damaged tissue without the need for an external power source. They exhibit piezoelectricity and good biological properties similar to those of natural bone and have shown great potential in bone tissue engineering. This study aims to present an overview of the relationship between electrical stimulation and bone repair as well as the principle of the piezoelectric effect, emphasizing the material characteristics, research progress and application of piezoelectric ceramics in bone tissue regeneration. The limitations of piezoelectric ceramics in promoting osteogenesis by electrical stimulation were also analysed. Overall, this review comprehensively emphasized the essential characteristics of piezoelectric ceramics and pointed out the new direction for the future development of piezoelectric ceramics.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135310700","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}
Qing-Xia Zhu, Liu Li, Wan-Ting Xu, Quan-Yi Nie, Yun-Long Xu, Jia-Xin Liu
To avoid sudden release of fluoride, F-substituted hydroxyapatite (FHA) porous microspheres were prepared for the treatment of F-deficiency tissues. In the absence of any template-directing reagents, FHA microspheres with diameters of about 30 ?m were successfully fabricated via hydrothermal method with urea as homogeneous precipitant to regulate the nucleation, growth and self-assembly process. Urea concentration and hydrothermal temperature played an important role in the formation and regulation of spherical hydroxyapatite. The synthesized FHA microspheres with large specific surface area, large pore volume and complex porous structure were efficient for the adsorption and long-term stable release of ionic extracts. Concentration of F- ions in physiological salt solution was maintained in the range of the therapeutic window without exceeding the toxic threshold within 30 days. The ionic extracts of FHA porous microspheres promoted the proliferation of human osteoblast-like cells (MG-63). The fabricated FHA microspheres may be a potential candidate as bioactive fluoride-release carriers for the treatment of osteoporosis and bone defects.
{"title":"Fluorine substituted hydroxyapatite microspheres: Template-free hydrothermal synthesis and sustained fluoride-releasing properties","authors":"Qing-Xia Zhu, Liu Li, Wan-Ting Xu, Quan-Yi Nie, Yun-Long Xu, Jia-Xin Liu","doi":"10.2298/pac2303248z","DOIUrl":"https://doi.org/10.2298/pac2303248z","url":null,"abstract":"To avoid sudden release of fluoride, F-substituted hydroxyapatite (FHA) porous microspheres were prepared for the treatment of F-deficiency tissues. In the absence of any template-directing reagents, FHA microspheres with diameters of about 30 ?m were successfully fabricated via hydrothermal method with urea as homogeneous precipitant to regulate the nucleation, growth and self-assembly process. Urea concentration and hydrothermal temperature played an important role in the formation and regulation of spherical hydroxyapatite. The synthesized FHA microspheres with large specific surface area, large pore volume and complex porous structure were efficient for the adsorption and long-term stable release of ionic extracts. Concentration of F- ions in physiological salt solution was maintained in the range of the therapeutic window without exceeding the toxic threshold within 30 days. The ionic extracts of FHA porous microspheres promoted the proliferation of human osteoblast-like cells (MG-63). The fabricated FHA microspheres may be a potential candidate as bioactive fluoride-release carriers for the treatment of osteoporosis and bone defects.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135310722","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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