Ítalo Leite de Camargo, J. Lovo, R. Erbereli, E. Bock, C. Fortulan
The development of photosensitive ceramic slurries for vat photopolymerization (stereolithography or digital light processing) has received much effort in recent years. However, many of these ceramic suspensions have high viscosity and they are suitable for use only on equipment, specialized in ceramic additive manufacturing. In this work, ceramic manufacturing using photocurable slurries was tested in a low-cost vat photopolymerization printer and in silicone moulds for UV-casting replication, with the latter approach still scarcely explored in the literature. Both processes were able to produce ceramic parts. The UV-casting replication was able to work with more viscous photocurable ceramic slurries and proved more suitable for the manufacturing of ceramic parts with larger cross-sections, providing pieces with improved flexural strength to those produced by additive manufacturing. This work presents the possibility of UV-casting photosensitive slurries to manufacture ceramics, an approach that could be easily adopted without high equipment costs.
{"title":"Fabrication of ceramics using photosensitive slurries: A comparison between UV-casting replication and vat photopolymerization 3D printing","authors":"Ítalo Leite de Camargo, J. Lovo, R. Erbereli, E. Bock, C. Fortulan","doi":"10.2298/pac2202153c","DOIUrl":"https://doi.org/10.2298/pac2202153c","url":null,"abstract":"The development of photosensitive ceramic slurries for vat photopolymerization (stereolithography or digital light processing) has received much effort in recent years. However, many of these ceramic suspensions have high viscosity and they are suitable for use only on equipment, specialized in ceramic additive manufacturing. In this work, ceramic manufacturing using photocurable slurries was tested in a low-cost vat photopolymerization printer and in silicone moulds for UV-casting replication, with the latter approach still scarcely explored in the literature. Both processes were able to produce ceramic parts. The UV-casting replication was able to work with more viscous photocurable ceramic slurries and proved more suitable for the manufacturing of ceramic parts with larger cross-sections, providing pieces with improved flexural strength to those produced by additive manufacturing. This work presents the possibility of UV-casting photosensitive slurries to manufacture ceramics, an approach that could be easily adopted without high equipment costs.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580505","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}
Calcium manganate (CMO) is a promising n-type semiconductor for thermoelectric applications due to its intrinsic properties. Still, these properties are highly dependent on the processing route used to produce these materials. In this work, properties of the polycrystalline CMO ceramics are reported by studying samples obtained from powders synthesized by a modified Pechini method and sintered at 1543K for 1, 3, 6, 12 and 24 h. Crystallographic parameters of the resulting phases were determined from X-ray diffraction patterns. The ceramics sintered for 6 h has the highest density (94.8%TD), while the CMO-1h sample (sintered only 1 h) presented the lowest density (77.2%TD) due to a large amount of secondary phase and short sintering time. The crystallite sizes of the CMO particles reached 49.2 nm; meanwhile, the grain sizes were in the range from 1.04 to 4.85 ?m. Seebeck coefficient has a negative value, characterizing an n-type material, and its value approached ?350 ?V/K at 873K. The sample sintered for 1 h has the lowest value of thermal conductivity (3.3W/mK), while the ceramics sintered for 3 h reached maximum electrical conductivity value (1830 S/m), both at 873K. In addition, this high conductivity of the ceramics sintered for 3 h contributed to it having the highest ZT value of about 0.039.
{"title":"Thermoelectric properties of CaMnO3 ceramics produced by using powder synthesized by modified Pechini method","authors":"S. Torres, J. Rosa, D. Thomazini, M. Gelfuso","doi":"10.2298/pac2202115t","DOIUrl":"https://doi.org/10.2298/pac2202115t","url":null,"abstract":"Calcium manganate (CMO) is a promising n-type semiconductor for thermoelectric applications due to its intrinsic properties. Still, these properties are highly dependent on the processing route used to produce these materials. In this work, properties of the polycrystalline CMO ceramics are reported by studying samples obtained from powders synthesized by a modified Pechini method and sintered at 1543K for 1, 3, 6, 12 and 24 h. Crystallographic parameters of the resulting phases were determined from X-ray diffraction patterns. The ceramics sintered for 6 h has the highest density (94.8%TD), while the CMO-1h sample (sintered only 1 h) presented the lowest density (77.2%TD) due to a large amount of secondary phase and short sintering time. The crystallite sizes of the CMO particles reached 49.2 nm; meanwhile, the grain sizes were in the range from 1.04 to 4.85 ?m. Seebeck coefficient has a negative value, characterizing an n-type material, and its value approached ?350 ?V/K at 873K. The sample sintered for 1 h has the lowest value of thermal conductivity (3.3W/mK), while the ceramics sintered for 3 h reached maximum electrical conductivity value (1830 S/m), both at 873K. In addition, this high conductivity of the ceramics sintered for 3 h contributed to it having the highest ZT value of about 0.039.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580613","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}
Ce0.82Dy0.155Sr0.025O2-? (SDDC) powder was synthesized by a sucrose-pectin modified sol-gel process. The powder was pressed and sintered at different temperatures, 1200, 1250 and 1300?C, to prepare dense ceramics with a relative density of 91, 93 and 95%TD, respectively. Crystal structure and phase composition were analysed by XRD using Rietveld refinement. The sample compositional analysis and element mapping were carried out by energy-dispersive spectroscopy. Microstructure images were recorded by scanning electron microscope. The electrical properties were measured by an impedance analyser. The grain resistance and the grain boundary resistance changed with the increased grain size. The SDDC electrolyte sintered at 1300?C exhibits an enhanced total electrical conductivity of 2.45?10?2 S/cm at 700?C and the activation energy of 0.76 eV. The porosity corrections are applied to the Bricklayer model to calculate the specific grain and grain boundary conductivities.
{"title":"Effect of sintering temperature on microstructure and electrical properties of Ce0.82Dy0.155Sr0.025O2-δ electrolyte","authors":"S. Ramesh","doi":"10.2298/pac2202175r","DOIUrl":"https://doi.org/10.2298/pac2202175r","url":null,"abstract":"Ce0.82Dy0.155Sr0.025O2-? (SDDC) powder was synthesized by a sucrose-pectin modified sol-gel process. The powder was pressed and sintered at different temperatures, 1200, 1250 and 1300?C, to prepare dense ceramics with a relative density of 91, 93 and 95%TD, respectively. Crystal structure and phase composition were analysed by XRD using Rietveld refinement. The sample compositional analysis and element mapping were carried out by energy-dispersive spectroscopy. Microstructure images were recorded by scanning electron microscope. The electrical properties were measured by an impedance analyser. The grain resistance and the grain boundary resistance changed with the increased grain size. The SDDC electrolyte sintered at 1300?C exhibits an enhanced total electrical conductivity of 2.45?10?2 S/cm at 700?C and the activation energy of 0.76 eV. The porosity corrections are applied to the Bricklayer model to calculate the specific grain and grain boundary conductivities.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580715","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}
Yue-Sheng Wang, Xin Shi, Miaomiao Liu, Yifa Yang, Qilong Gao, B. Zhu, L. Xu
Ta doped TiN films were prepared on glass substrates by DC magnetron co-sputtering. The structure and properties of the obtained (Ti,Ta)N film were characterized by X-ray diffraction, Raman spectroscopy, ultraviolet/visible/near-infrared spectrophotometer and four probes method. The results show that with the increase of the sputtering power (PTa) for Ta target, the amount of Ta added to TiN lattice increases, resulting in a slight distortion of TiN lattice and stress transformation in the film. Correspondingly, the optical and electrical properties of the film changed. Raman spectrum was deconvoluted into five Lorentz peaks in the range of 50-1400 cm?1 and a new Raman peak appeared in all samples due to the substitution of Ta for Ti. The analysis of deconvolution results shows that the peak positions of different phonon modes and FWHM change, which may be related to the change of stress in the thin films caused by adding Ta to TiN lattice. The sample prepared with power of 50W has the maximum infrared emissivity of 1.35 and 0.43 at 2.5 and 25 ?m wavelengths, respectively, indicating that (Ti,Ta)N film is promising candidate for replacing TiN in Low-E glass.
{"title":"Structure and properties of Ta doped TiN films prepared using different sputtering powers for Ta target","authors":"Yue-Sheng Wang, Xin Shi, Miaomiao Liu, Yifa Yang, Qilong Gao, B. Zhu, L. Xu","doi":"10.2298/pac2203191w","DOIUrl":"https://doi.org/10.2298/pac2203191w","url":null,"abstract":"Ta doped TiN films were prepared on glass substrates by DC magnetron co-sputtering. The structure and properties of the obtained (Ti,Ta)N film were characterized by X-ray diffraction, Raman spectroscopy, ultraviolet/visible/near-infrared spectrophotometer and four probes method. The results show that with the increase of the sputtering power (PTa) for Ta target, the amount of Ta added to TiN lattice increases, resulting in a slight distortion of TiN lattice and stress transformation in the film. Correspondingly, the optical and electrical properties of the film changed. Raman spectrum was deconvoluted into five Lorentz peaks in the range of 50-1400 cm?1 and a new Raman peak appeared in all samples due to the substitution of Ta for Ti. The analysis of deconvolution results shows that the peak positions of different phonon modes and FWHM change, which may be related to the change of stress in the thin films caused by adding Ta to TiN lattice. The sample prepared with power of 50W has the maximum infrared emissivity of 1.35 and 0.43 at 2.5 and 25 ?m wavelengths, respectively, indicating that (Ti,Ta)N film is promising candidate for replacing TiN in Low-E glass.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581322","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}
Needle-like SiC whiskers were synthesised by microwave heating using graphite sheets and tetraethoxysilane (TEOS) as raw materials. It was found that SiC powder could be synthesised at 1000?C for 10min, lower than that of samples made from a granular C source. Furthermore, the heating rate of the samples made with graphite sheets was higher than that of a granular C source. The main morphology of the SiC whiskers was needle-like, which appeared when samples were heated at 1200?C for 10min. Size of the SiC whiskers made with graphite sheets was more uniform than that of a granular C source, which was attributed to the 2D thermal effect. Moreover, the size and the amount of the SiC whiskers increased as the heating temperature increased from 1200 to 1400?C for 10min. The SiC whiskers were oxidised and decomposed into SiC particles when heated to 1500?C for 10min and only SiC particles existed when longer holding times were used.
{"title":"Study on mechanisms of microwave synthesis of SiC crystal from sheet carbon source","authors":"Bozhen Song, Chenjiang Dong, Xinyue Zhang, B. Fan, Jingqing Gao, Rui Zhang","doi":"10.2298/pac2203283s","DOIUrl":"https://doi.org/10.2298/pac2203283s","url":null,"abstract":"Needle-like SiC whiskers were synthesised by microwave heating using graphite sheets and tetraethoxysilane (TEOS) as raw materials. It was found that SiC powder could be synthesised at 1000?C for 10min, lower than that of samples made from a granular C source. Furthermore, the heating rate of the samples made with graphite sheets was higher than that of a granular C source. The main morphology of the SiC whiskers was needle-like, which appeared when samples were heated at 1200?C for 10min. Size of the SiC whiskers made with graphite sheets was more uniform than that of a granular C source, which was attributed to the 2D thermal effect. Moreover, the size and the amount of the SiC whiskers increased as the heating temperature increased from 1200 to 1400?C for 10min. The SiC whiskers were oxidised and decomposed into SiC particles when heated to 1500?C for 10min and only SiC particles existed when longer holding times were used.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581445","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 aim of this study was to investigate the bone-like apatite forming ability of bioglass coated bones by immersing them in simulated body fluid (SBF). Various types of bioactive coatings with an average thickness of 15 ?m were deposited on the surface of the cortical bovine bone by vacuum assisted infiltration.More intense apatite crystallization was observed using additives such as hydroxyapatite, sintered bone and ?-whitlockite in the base glass. The dissolution properties of the scaffolds were determined by ICP-OES and XRF methods. The consequence of the release of Ca and P during immersion in SBF on the mechanical properties was observed through measurements of microhardness, bending and compressive strength.
{"title":"Apatite-forming ability of bioglass coated bovine bone scaffolds","authors":"M. Jakab, M. Enisz-Bódogh, K. Kovacs","doi":"10.2298/pac2203276j","DOIUrl":"https://doi.org/10.2298/pac2203276j","url":null,"abstract":"The aim of this study was to investigate the bone-like apatite forming ability of bioglass coated bones by immersing them in simulated body fluid (SBF). Various types of bioactive coatings with an average thickness of 15 ?m were deposited on the surface of the cortical bovine bone by vacuum assisted infiltration.More intense apatite crystallization was observed using additives such as hydroxyapatite, sintered bone and ?-whitlockite in the base glass. The dissolution properties of the scaffolds were determined by ICP-OES and XRF methods. The consequence of the release of Ca and P during immersion in SBF on the mechanical properties was observed through measurements of microhardness, bending and compressive strength.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581637","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}
M. Stojmenović, N. Nisic, M. Zunic, F. Basoli, Jelena Gulicovki, I. Ristovic, M. Kragović
Nanosized multi-doped ceria with composition Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-? (CNSGDY) as perspective solid ionic conductor was obtained by modified glycine-nitrate procedure (MGNP) and room temperature self-propagating reaction (SPRT). The pressed pellets of both powders were sintered at 1550?C for 2 h in an air atmosphere. The obtained sintered samples were characterized by XRPD, Raman spectroscopy, FESEM, EDS and EIS methods. Despite a high temperature of sintering, XRPD and FESEM analyses of the samples confirmed appropriate dimensions of grains with fluorite structure. Overall concentration of introduced dopants (x = 0.2) in the structure of CeO2 after the sintering process was confirmed by EDS analysis. After sintering, Raman spectroscopy confirmed retention of the oxygen vacancies in the ceria lattice, which is in accordance with the improvement of ionic conductivity of solid ionic conductors. The highest value of total conductivity was obtained for the sintered MGNP sample at 700?C (4.22 ? 10?2 S cm?1), with the corresponding activation energy of 0.26 eV.
Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-?采用改良甘氨酸-硝酸盐法(MGNP)和室温自传播反应(SPRT)制备了透视固体离子导体(CNSGDY)。两种粉末的压小球在1550℃下烧结。在空气环境中温度升高2小时。采用XRPD、拉曼光谱、FESEM、EDS和EIS等方法对烧结样品进行了表征。尽管烧结温度较高，但样品的XRPD和FESEM分析证实了适当尺寸的萤石结构晶粒。通过能谱分析确定了烧结过程后CeO2结构中引入掺杂剂的总浓度(x = 0.2)。烧结后，拉曼光谱证实了氧化铈晶格中氧空位的保留，这与固体离子导体离子电导率的提高是一致的。烧结MGNP样品的总电导率在700℃时达到最高值。C (4.22 ?10？2 S cm?1)，对应的活化能为0.26 eV。
{"title":"Development of a new system of solid ionic conductors based on multi-doped ceria for application in IT-SOFCs","authors":"M. Stojmenović, N. Nisic, M. Zunic, F. Basoli, Jelena Gulicovki, I. Ristovic, M. Kragović","doi":"10.2298/pac2204391s","DOIUrl":"https://doi.org/10.2298/pac2204391s","url":null,"abstract":"Nanosized multi-doped ceria with composition Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-? (CNSGDY) as perspective solid ionic conductor was obtained by modified glycine-nitrate procedure (MGNP) and room temperature self-propagating reaction (SPRT). The pressed pellets of both powders were sintered at 1550?C for 2 h in an air atmosphere. The obtained sintered samples were characterized by XRPD, Raman spectroscopy, FESEM, EDS and EIS methods. Despite a high temperature of sintering, XRPD and FESEM analyses of the samples confirmed appropriate dimensions of grains with fluorite structure. Overall concentration of introduced dopants (x = 0.2) in the structure of CeO2 after the sintering process was confirmed by EDS analysis. After sintering, Raman spectroscopy confirmed retention of the oxygen vacancies in the ceria lattice, which is in accordance with the improvement of ionic conductivity of solid ionic conductors. The highest value of total conductivity was obtained for the sintered MGNP sample at 700?C (4.22 ? 10?2 S cm?1), with the corresponding activation energy of 0.26 eV.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582478","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}
V. Ussui, D. Lazar, N. D. de Lima, A. Arata, Fabio Ribeiro, G. Dalpian, J. Marchi, José Octavio Paschoal
Yttria-stabilized tetragonal zirconia (Y-TZP) ceramics have excellent mechanical properties. However, such materials cannot undergo plastic deformation at room temperature due to their high hardness and brittleness values, hindering machinability. To overcome these limitations, we propose a zirconia-yttria-titania ceramics, based on zirconia containing 3mol% yttria and up to 15mol% titania. The zirconia-yttria-titania powders were synthesized by co-precipitation method, uniaxially pressed and sintered at 1400?C/5 h. Sample characterizations were carried out by X-ray diffraction, scanning electron microscopy and mechanical properties through Vickers hardness and toughness measurements. Compared to the Y-TZP ceramics, the yttria stabilised tetragonal zirconia ceramics co-doped with 10mol%Ti showed noticeable increase of tetragonality parameter, higher toughness and lower hardness values, indicating plasticity at room temperature. Furthermore, the atomistic simulation by Density Functional Theory methodology suggests the occurrence of spatial arrangement of the atoms, explaining the proposed plasticity.
{"title":"Room temperature plasticity of zirconia-yttria-titania ceramics: Experimental indications and structural modelling","authors":"V. Ussui, D. Lazar, N. D. de Lima, A. Arata, Fabio Ribeiro, G. Dalpian, J. Marchi, José Octavio Paschoal","doi":"10.2298/pac2204367u","DOIUrl":"https://doi.org/10.2298/pac2204367u","url":null,"abstract":"Yttria-stabilized tetragonal zirconia (Y-TZP) ceramics have excellent mechanical properties. However, such materials cannot undergo plastic deformation at room temperature due to their high hardness and brittleness values, hindering machinability. To overcome these limitations, we propose a zirconia-yttria-titania ceramics, based on zirconia containing 3mol% yttria and up to 15mol% titania. The zirconia-yttria-titania powders were synthesized by co-precipitation method, uniaxially pressed and sintered at 1400?C/5 h. Sample characterizations were carried out by X-ray diffraction, scanning electron microscopy and mechanical properties through Vickers hardness and toughness measurements. Compared to the Y-TZP ceramics, the yttria stabilised tetragonal zirconia ceramics co-doped with 10mol%Ti showed noticeable increase of tetragonality parameter, higher toughness and lower hardness values, indicating plasticity at room temperature. Furthermore, the atomistic simulation by Density Functional Theory methodology suggests the occurrence of spatial arrangement of the atoms, explaining the proposed plasticity.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582349","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}
Fe2TiO5 was synthesized via nonhydrolytic sol-gel method at 600?C. The effects of iron sources on the synthesis of Fe2TiO5 were investigated. It was demonstrated that Fe-O-Ti bonds will not be formed in the xerogels prepared by taking FeCl3 as iron source because it is strong Lewis acid and induces homocondensation. Fe-O-Ti bonds were formed in the xerogels prepared by using Fe(OC2H5)3 and FeOH(CH3COO)2 as iron sources. However, the hydroxyl group in FeOH(CH3COO)2 easily leads to homocondensation and particles agglomeration. Thus, Fe(OC2H5)3 is optimal iron source with both excellent synthesis and particle dispersion effects.
采用非水解溶胶-凝胶法在600℃下合成了Fe2TiO5。研究了不同铁源对Fe2TiO5合成的影响。结果表明，以FeCl3为铁源制备的干凝胶不会形成Fe-O-Ti键，因为FeCl3是强路易斯酸，会引起均缩合。以Fe(OC2H5)3和FeOH(CH3COO)2为铁源制备的干凝胶中形成了Fe- o - ti键。然而，FeOH(CH3COO)2中的羟基容易导致均缩聚和颗粒团聚。因此，Fe(OC2H5)3是最理想的铁源，具有良好的合成效果和粒子分散效果。
{"title":"Effect of iron source on nonhydrolytic sol-gel synthesis of Fe2TiO5","authors":"Feng Jiang, Guo Feng, Lina Yin, Qianqian Zhao, Yun-Hao Yu, Weihui Jiang","doi":"10.2298/pac2201007j","DOIUrl":"https://doi.org/10.2298/pac2201007j","url":null,"abstract":"Fe2TiO5 was synthesized via nonhydrolytic sol-gel method at 600?C. The effects of iron sources on the synthesis of Fe2TiO5 were investigated. It was demonstrated that Fe-O-Ti bonds will not be formed in the xerogels prepared by taking FeCl3 as iron source because it is strong Lewis acid and induces homocondensation. Fe-O-Ti bonds were formed in the xerogels prepared by using Fe(OC2H5)3 and FeOH(CH3COO)2 as iron sources. However, the hydroxyl group in FeOH(CH3COO)2 easily leads to homocondensation and particles agglomeration. Thus, Fe(OC2H5)3 is optimal iron source with both excellent synthesis and particle dispersion effects.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579437","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}
In this paper, barium ferrite powders were synthesized by sol-gel method, calcined at different temperatures, and on this basis the corresponding ceramics were prepared. The effects of calcination temperature on the structure, magnetic, dielectric and multiferroic properties of BaFe12O19 ceramics were studied. XRD results confirmed similarity between powders and ceramics, where dominant phase is BaFe12O19 and a small amount of an apparent BaFe2O4 impurity phase was formed at lower calcination temperature. The impurity BaFe2O4 phase is the main reason for decreasing powder magnetization. The maximum dielectric constant of 100 (at 10 kHz) and maximum remanent polarization, remanent magnetization and saturation magnetization of 0.46 ?C/cm2, 47.37 emu/g and 79.96 emu/g, respectively, were obtained in the barium ferrite ceramics prepared from the powder calcined at 1100?C. This research could be the basis for the study of single-phase multiferroic materials and the development of multi-order electronic devices.
{"title":"Influence of calcination temperature on structure and multiferroic properties of barium ferrite ceramics","authors":"Zhixin Zeng, Q. Zhang, Heng Wu, Mengshuang Lan, Hongmin Ao, Wenchuan Li, Chuang Zhou, Jizhuang He, S. Xing, X. Deng, R. Gao","doi":"10.2298/pac2202106z","DOIUrl":"https://doi.org/10.2298/pac2202106z","url":null,"abstract":"In this paper, barium ferrite powders were synthesized by sol-gel method, calcined at different temperatures, and on this basis the corresponding ceramics were prepared. The effects of calcination temperature on the structure, magnetic, dielectric and multiferroic properties of BaFe12O19 ceramics were studied. XRD results confirmed similarity between powders and ceramics, where dominant phase is BaFe12O19 and a small amount of an apparent BaFe2O4 impurity phase was formed at lower calcination temperature. The impurity BaFe2O4 phase is the main reason for decreasing powder magnetization. The maximum dielectric constant of 100 (at 10 kHz) and maximum remanent polarization, remanent magnetization and saturation magnetization of 0.46 ?C/cm2, 47.37 emu/g and 79.96 emu/g, respectively, were obtained in the barium ferrite ceramics prepared from the powder calcined at 1100?C. This research could be the basis for the study of single-phase multiferroic materials and the development of multi-order electronic devices.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"30 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580540","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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