J. Vujancevic, Andjelika Bjelajac, K. Veltruská, V. Matolín, Z. Siketić, G. Provatas, M. Jakšić, G. Stan, G. Socol, I. Mihăilescu, V. Pavlović, D. Janackovic
Pure Ti films deposited by radio-frequency magnetron sputtering on FTO glass were anodized to fabricate TiO2 nanotubes (NTs) arrays. The TiO2 NTs/FTO samples were sintered at 450, 550 and 630?C, in ambient air. The thermal treatment did not influence the crystal phase composition, preserving in all cases the anatase single phase. As expected, the crystalline anatase quality improved with the annealing temperature. Nevertheless, slight differences in nanotubular morphology, such as the appearance of grains inside the walls, were observed in the case of the sample sintered at 630?C. Chemical analysis by X-ray Photoelectron Spectroscopy of annealed samples revealed the presence of Sn inside TiO2 NTs, due to diffusion of Sn from the substrate to TiO2. For the substrate was used FTO glass whose top layer consists of SnO2 doped with F. Rutherford Backscattering Spectrometry and Time-of-Flight Elastic Recoil Detection Analysis were carried out to study the elemental depth profile of the films. It was found that the temperature of sintering controls the Sn diffusion inside TiO2 film. Sn atoms diffuse towards the TiO2 NTs surface for the samples annealed at 450 and 550?C. The diffusion is however hindered in the case of the heat treatment at 630?C. Besides, the Ti diffusion into the SnO2 underlayer was observed, together with the formation of TiO2/SnO2 interfaces. One then expected but not a great difference in absorption between samples, since all contained anatase phase, as confirmed by Diffuse Reflectance Spectroscopy. A higher amount of Sn was however detected for the sample annealed at 550?C, which accounts for a slight red absorption shift. The importance of controlling the annealing parameters of the anodized TiO2/FTO structures was highlighted through the formation of TiO2-SnO2 interfaces and the Sn insertion from FTO, which can play an essential role in increasing the photoperformances of TiO2 NTs/FTO based structures of photovoltaic cells.
{"title":"TiO2 nanotubes film/FTO glass interface: Thermal treatment effects","authors":"J. Vujancevic, Andjelika Bjelajac, K. Veltruská, V. Matolín, Z. Siketić, G. Provatas, M. Jakšić, G. Stan, G. Socol, I. Mihăilescu, V. Pavlović, D. Janackovic","doi":"10.2298/sos2202235v","DOIUrl":"https://doi.org/10.2298/sos2202235v","url":null,"abstract":"Pure Ti films deposited by radio-frequency magnetron sputtering on FTO glass were anodized to fabricate TiO2 nanotubes (NTs) arrays. The TiO2 NTs/FTO samples were sintered at 450, 550 and 630?C, in ambient air. The thermal treatment did not influence the crystal phase composition, preserving in all cases the anatase single phase. As expected, the crystalline anatase quality improved with the annealing temperature. Nevertheless, slight differences in nanotubular morphology, such as the appearance of grains inside the walls, were observed in the case of the sample sintered at 630?C. Chemical analysis by X-ray Photoelectron Spectroscopy of annealed samples revealed the presence of Sn inside TiO2 NTs, due to diffusion of Sn from the substrate to TiO2. For the substrate was used FTO glass whose top layer consists of SnO2 doped with F. Rutherford Backscattering Spectrometry and Time-of-Flight Elastic Recoil Detection Analysis were carried out to study the elemental depth profile of the films. It was found that the temperature of sintering controls the Sn diffusion inside TiO2 film. Sn atoms diffuse towards the TiO2 NTs surface for the samples annealed at 450 and 550?C. The diffusion is however hindered in the case of the heat treatment at 630?C. Besides, the Ti diffusion into the SnO2 underlayer was observed, together with the formation of TiO2/SnO2 interfaces. One then expected but not a great difference in absorption between samples, since all contained anatase phase, as confirmed by Diffuse Reflectance Spectroscopy. A higher amount of Sn was however detected for the sample annealed at 550?C, which accounts for a slight red absorption shift. The importance of controlling the annealing parameters of the anodized TiO2/FTO structures was highlighted through the formation of TiO2-SnO2 interfaces and the Sn insertion from FTO, which can play an essential role in increasing the photoperformances of TiO2 NTs/FTO based structures of photovoltaic cells.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809409","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}
Waste glass and reclaimed brick are types of construction and demolition waste (C&DW) that could potentially be used as secondary raw materials in the production of ceramics. Ceramics based on clay, waste demolished brick (5-15 wt.%) and waste glass (5-20 wt.%) were produced by pressing (P = 68 MPa) and subsequently sintered at 900, 950, 1000, and 1050 oC for one hour. The physical and mechanical properties of the ceramics obtained were evaluated. The addition of demolished brick decreased the density and mechanical properties of the clay specimens and increased the water absorption. The incorporation of waste glass improved the sintering behavior and its mechanical properties. The addition of 20 wt.% waste glass and 10 wt.% waste demolished brick into the clay matrix improved the flexural strength by up to 20.6 % and decreased the water absorption by up to 22 %. The approach presented promotes an opportunity to recycle construction and demolition waste into alternative resource materials, and represents a positive contribution to the environment.
{"title":"The effect of the addition of construction & demolition waste on the properties of clay-based ceramics","authors":"B. Angjusheva, V. Ducman, E. Fidanchevski","doi":"10.2298/sos2203359a","DOIUrl":"https://doi.org/10.2298/sos2203359a","url":null,"abstract":"Waste glass and reclaimed brick are types of construction and demolition waste (C&DW) that could potentially be used as secondary raw materials in the production of ceramics. Ceramics based on clay, waste demolished brick (5-15 wt.%) and waste glass (5-20 wt.%) were produced by pressing (P = 68 MPa) and subsequently sintered at 900, 950, 1000, and 1050 oC for one hour. The physical and mechanical properties of the ceramics obtained were evaluated. The addition of demolished brick decreased the density and mechanical properties of the clay specimens and increased the water absorption. The incorporation of waste glass improved the sintering behavior and its mechanical properties. The addition of 20 wt.% waste glass and 10 wt.% waste demolished brick into the clay matrix improved the flexural strength by up to 20.6 % and decreased the water absorption by up to 22 %. The approach presented promotes an opportunity to recycle construction and demolition waste into alternative resource materials, and represents a positive contribution to the environment.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809865","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}
Nickel chromite nanoparticles were prepared by sol-gel auto combustion method followed by calcination at different temperatures, 700, 900, 1100 and 1300oC for 8h. The prepared nanoparticles were characterized by XRD, SEM, EDS, FTIR and UV-Vis spectroscopy. From the XRD patterns, the Miller indices (hkl) were identified for all the prominent peaks for all the samples, it was clear that the compound crystallized according to spinel structure with a space group of Fd3m. SEM images showed non-uniform agglomerated fragments having a lot of voids and pores. UsingScherrer method, the crystallite size was calculated and found gradually increasing trend with the calcination temperature from 13.73 to 22.33 nm, where as the average grain size was increased from 140.00 to 163.46 nm with calcination temperature. FTIR spectra showed six fundamental absorption bands in the range 500 to 3470 cm-1, whereas the two absorption bands in the range 500-625 cm-1 confirmed the bonding vibrations of metal-oxygen bonds situated at octahedral and tetrahedral sites. UV-Vis spectroscopy was carried out in the wavelength range 200-800 nm and the optical band gap (Eg) was observed in the range 4.2129-4.3115 eV.
{"title":"Influence of calcination temperature on physical and optical properties of nickel chromite nanoparticles","authors":"K. Kumar, S. Bhavani","doi":"10.2298/sos2204457k","DOIUrl":"https://doi.org/10.2298/sos2204457k","url":null,"abstract":"Nickel chromite nanoparticles were prepared by sol-gel auto combustion method followed by calcination at different temperatures, 700, 900, 1100 and 1300oC for 8h. The prepared nanoparticles were characterized by XRD, SEM, EDS, FTIR and UV-Vis spectroscopy. From the XRD patterns, the Miller indices (hkl) were identified for all the prominent peaks for all the samples, it was clear that the compound crystallized according to spinel structure with a space group of Fd3m. SEM images showed non-uniform agglomerated fragments having a lot of voids and pores. UsingScherrer method, the crystallite size was calculated and found gradually increasing trend with the calcination temperature from 13.73 to 22.33 nm, where as the average grain size was increased from 140.00 to 163.46 nm with calcination temperature. FTIR spectra showed six fundamental absorption bands in the range 500 to 3470 cm-1, whereas the two absorption bands in the range 500-625 cm-1 confirmed the bonding vibrations of metal-oxygen bonds situated at octahedral and tetrahedral sites. UV-Vis spectroscopy was carried out in the wavelength range 200-800 nm and the optical band gap (Eg) was observed in the range 4.2129-4.3115 eV.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68810140","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}
Tijana Maksimovic, J. Maksimović, P. Tančić, N. Potkonjak, Z. Nedić, Ljubinka G. Joksović, Maja C. Pagnacco
The calcium phosphate tungsten bronze (Ca-PWB) has been synthesized and characterized (TGA, DSC, XRPD, FTIR, SEM). The influence of solid insoluble materials Ca- PWB, as well as lithium doped (Li-PWB) and cation free phosphate tungsten (PWB) bronzes on the oscillatory Briggs-Rauscher (BR) reaction dynamics, is compared. The results show that doping with Li and Ca reduces sensitivity of the BR reaction towards bronzes addition. These findings suggest the usage of the BR reaction as an innovative method for testing of different properties of bronze material. The behavior of PWB in the BR reaction is significantly changed with divalent cation (Ca2+) doping. The reasons for the different bronzes behavior were found in their calculated unit cell volumes. Namely, the compressed Ca-PWB unit cell volume indicates the difficult availability of the active site for heterogeneous catalysis. Hence, the linear correlation (slope) of the BR oscillogram?s length (?osc) vs. mass of bronze in BR reaction might be considered as a new parameter for the evaluation of the bronzes catalytic activity.
{"title":"A possible connection between phosphate tungsten bronzes properties and Briggs-Rauscher oscillatory reaction response","authors":"Tijana Maksimovic, J. Maksimović, P. Tančić, N. Potkonjak, Z. Nedić, Ljubinka G. Joksović, Maja C. Pagnacco","doi":"10.2298/sos2102223m","DOIUrl":"https://doi.org/10.2298/sos2102223m","url":null,"abstract":"The calcium phosphate tungsten bronze (Ca-PWB) has been synthesized and\u0000 characterized (TGA, DSC, XRPD, FTIR, SEM). The influence of solid insoluble\u0000 materials Ca- PWB, as well as lithium doped (Li-PWB) and cation free\u0000 phosphate tungsten (PWB) bronzes on the oscillatory Briggs-Rauscher (BR)\u0000 reaction dynamics, is compared. The results show that doping with Li and Ca\u0000 reduces sensitivity of the BR reaction towards bronzes addition. These\u0000 findings suggest the usage of the BR reaction as an innovative method for\u0000 testing of different properties of bronze material. The behavior of PWB in\u0000 the BR reaction is significantly changed with divalent cation (Ca2+) doping.\u0000 The reasons for the different bronzes behavior were found in their\u0000 calculated unit cell volumes. Namely, the compressed Ca-PWB unit cell volume\u0000 indicates the difficult availability of the active site for heterogeneous\u0000 catalysis. Hence, the linear correlation (slope) of the BR oscillogram?s\u0000 length (?osc) vs. mass of bronze in BR reaction might be considered as a new\u0000 parameter for the evaluation of the bronzes catalytic activity.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41960884","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}
Ljiljana Miličić, A. Terzic, L. Pezo, N. Mijatović, I. Brčeski, N. Vukelic
Rare earth elements (REE) are frequently referred to as ingredients for enhancements in modern industry, as they are extensively applied in many industrial branches due to their accented electro-magnetic and optical properties. REE have end-utilizations as catalysts, magnets, and as dopants for ceramic materials. Rare earth minerals are scarce therefore the unconventional REE-containing resources such as waste materials and industrial byproducts are continuously being investigated. Coal combustion products comprise REE concentrations varying between 200 ppm and 1500 ppm. This quantity can be isolated though the extraction procedure. In this study, the five stages extraction was conducted on the coal combustion ash from the selected landfill site. The extractions of 32 elements (As, Ga, Ce, Be, Ge, Nd, Cr, Zr, Eu, Cu, Nb, Gd, Co, Mo, Dy, Li, Ag, W, Mn, Cd, Au, Ni, In, Hg, Pb, Sn, Tl, V, Sb, Th, Zn, and La) were conveyed. Chemical analyses were conducted via XRF, ICP-OES, ICP-MS, and AAS techniques. The complexity of the obtained data was examined by Principal component analysis and Cluster analysis in order to derive interconnections between quantity of elements and landfill characteristics, as well as mutual relationships among the elements of interest, and to assess the accomplishment of REE recovery from the coal ash.
{"title":"Assessment of efficiency of rare earth elements recovery from lignite coal combustion ash via five-stage extraction","authors":"Ljiljana Miličić, A. Terzic, L. Pezo, N. Mijatović, I. Brčeski, N. Vukelic","doi":"10.2298/sos2102169m","DOIUrl":"https://doi.org/10.2298/sos2102169m","url":null,"abstract":"Rare earth elements (REE) are frequently referred to as ingredients for\u0000 enhancements in modern industry, as they are extensively applied in many\u0000 industrial branches due to their accented electro-magnetic and optical\u0000 properties. REE have end-utilizations as catalysts, magnets, and as dopants\u0000 for ceramic materials. Rare earth minerals are scarce therefore the\u0000 unconventional REE-containing resources such as waste materials and\u0000 industrial byproducts are continuously being investigated. Coal combustion\u0000 products comprise REE concentrations varying between 200 ppm and 1500 ppm.\u0000 This quantity can be isolated though the extraction procedure. In this\u0000 study, the five stages extraction was conducted on the coal combustion ash\u0000 from the selected landfill site. The extractions of 32 elements (As, Ga, Ce,\u0000 Be, Ge, Nd, Cr, Zr, Eu, Cu, Nb, Gd, Co, Mo, Dy, Li, Ag, W, Mn, Cd, Au, Ni,\u0000 In, Hg, Pb, Sn, Tl, V, Sb, Th, Zn, and La) were conveyed. Chemical analyses\u0000 were conducted via XRF, ICP-OES, ICP-MS, and AAS techniques. The complexity\u0000 of the obtained data was examined by Principal component analysis and\u0000 Cluster analysis in order to derive interconnections between quantity of\u0000 elements and landfill characteristics, as well as mutual relationships among\u0000 the elements of interest, and to assess the accomplishment of REE recovery\u0000 from the coal ash.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47155649","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}
Sa. Benkacem, K. Boudeghdegh, F. Zehani, M. Hamidouche, Y. Belhocine
In this paper, the use of local kaolin coming from Djebel Debbagh (denoted DD1) in the composition of ceramic glazes for sanitary ware was examined. Because of its natural abundance, low price and good characteristics, this kaolin represents an interesting economic alternative to other mineral clays. The chemical composition showed that this kaolin contains 38.49 wt.% Al2O3 and 44.85 wt.% SiO2. Two glazes based on kaolin DD1 denoted as GaDD1 and GbDD1 were prepared with conventional ceramic processing techniques at temperature 1250 oC. As a reference, another glaze (Gref) based on kaolin Remblend was also prepared in the same conditions. The samples were characterized with X-ray diffraction and Scanning Electron Microscope. The results revealed that zircon and quartz are the crystalline phases present in these glazes. In the sample GaDD1, it was found that the degree of whiteness is very high and reaches 93.30 %. However, the water absorption coefficient is low which is about 0.19 ? 0.04 %. In addition, the flexural strength and the Vickers microhardness are respectively, about 56.07 ? 5.61 MPa and 7952.80 ? 101.76 MPa. These properties are compatible with those of the glaze reference Gref and commercial sanitary ware glazes, indicating the potential use of kaolin DD1 in the production of glazed ceramic for sanitary ware applications.
{"title":"Preparation, microstructure studies and mechanical properties of glazes ceramic sanitary ware based on kaolin","authors":"Sa. Benkacem, K. Boudeghdegh, F. Zehani, M. Hamidouche, Y. Belhocine","doi":"10.2298/sos2102209b","DOIUrl":"https://doi.org/10.2298/sos2102209b","url":null,"abstract":"In this paper, the use of local kaolin coming from Djebel Debbagh (denoted\u0000 DD1) in the composition of ceramic glazes for sanitary ware was examined.\u0000 Because of its natural abundance, low price and good characteristics, this\u0000 kaolin represents an interesting economic alternative to other mineral\u0000 clays. The chemical composition showed that this kaolin contains 38.49 wt.%\u0000 Al2O3 and 44.85 wt.% SiO2. Two glazes based on kaolin DD1 denoted as GaDD1\u0000 and GbDD1 were prepared with conventional ceramic processing techniques at\u0000 temperature 1250 oC. As a reference, another glaze (Gref) based on kaolin\u0000 Remblend was also prepared in the same conditions. The samples were\u0000 characterized with X-ray diffraction and Scanning Electron Microscope. The\u0000 results revealed that zircon and quartz are the crystalline phases present\u0000 in these glazes. In the sample GaDD1, it was found that the degree of\u0000 whiteness is very high and reaches 93.30 %. However, the water absorption\u0000 coefficient is low which is about 0.19 ? 0.04 %. In addition, the flexural\u0000 strength and the Vickers microhardness are respectively, about 56.07 ? 5.61\u0000 MPa and 7952.80 ? 101.76 MPa. These properties are compatible with those of\u0000 the glaze reference Gref and commercial sanitary ware glazes, indicating the\u0000 potential use of kaolin DD1 in the production of glazed ceramic for sanitary\u0000 ware applications.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47069232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study is the first attempt to large-scale energy-efficient production of nanomagnetic Ni/NiO composites by using the autocombustion based on leaves or extract of corchorus olitorius. The as synthesized product can be characterized by using XRD, SEM, TEM and EDX techniques. The results confirm that the as synthesized materials consisted entirely of well crystalline Ni and NiO phases. The crystallinity of both Ni and NiO enhanced by increasing amount of the corchorus olitorius. However, the corchorus olitorius - treatment resulted in an increase in the crystallite size and lattice constant. The SEM analysis confirms formation of fragile, fluffy and spongy networks. The average of grain size for the as prepared particles was found to be 45 nm in agreement with the trend of the crystallite size calculated by using XRD technique. Furthermore, changing of nature and content of the corchorus olitorius brought about progressive modifications in the magnetic properties, namely, Ms, Mr, Mr/Ms, Hc and Ka, of the fabricated Ni/NiO nanocomposite according to the structural, morphological as well as microstructural variation. The saturation magnetization (Ms) of the sample with corchorus olitorius leaves was found to be 0.2383 emu/g while the Ms with corchorus olitorius extract was found to 6.977 emu/g. This was discussed in the light of finite size, surface and interface effects. Thus, we unveil a new approach for incandescent combustion synthesis via an innate approach for corchorus olitorius leaves in the directly fabrication for different nanocomposites.
{"title":"Incandescent combustion synthesis of nanomagnetic Ni/NiO composites","authors":"N. Deraz","doi":"10.2298/sos2102155d","DOIUrl":"https://doi.org/10.2298/sos2102155d","url":null,"abstract":"This study is the first attempt to large-scale energy-efficient production of\u0000 nanomagnetic Ni/NiO composites by using the autocombustion based on leaves\u0000 or extract of corchorus olitorius. The as synthesized product can be\u0000 characterized by using XRD, SEM, TEM and EDX techniques. The results confirm\u0000 that the as synthesized materials consisted entirely of well crystalline Ni\u0000 and NiO phases. The crystallinity of both Ni and NiO enhanced by increasing\u0000 amount of the corchorus olitorius. However, the corchorus olitorius -\u0000 treatment resulted in an increase in the crystallite size and lattice\u0000 constant. The SEM analysis confirms formation of fragile, fluffy and spongy\u0000 networks. The average of grain size for the as prepared particles was found\u0000 to be 45 nm in agreement with the trend of the crystallite size calculated\u0000 by using XRD technique. Furthermore, changing of nature and content of the\u0000 corchorus olitorius brought about progressive modifications in the magnetic\u0000 properties, namely, Ms, Mr, Mr/Ms, Hc and Ka, of the fabricated Ni/NiO\u0000 nanocomposite according to the structural, morphological as well as\u0000 microstructural variation. The saturation magnetization (Ms) of the sample\u0000 with corchorus olitorius leaves was found to be 0.2383 emu/g while the Ms\u0000 with corchorus olitorius extract was found to 6.977 emu/g. This was\u0000 discussed in the light of finite size, surface and interface effects. Thus,\u0000 we unveil a new approach for incandescent combustion synthesis via an innate\u0000 approach for corchorus olitorius leaves in the directly fabrication for\u0000 different nanocomposites.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47087927","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. Nenadovic, Danilo Kisić, M. Mirković, S. Nenadović, Ljiljana M. Kljajević
The implantation of high-density polyethylene (HDPE) has been conducted using Ag+ ions with energy of 60 keV, achieved fluences 1.5 and 10?1015 ions/cm2. Transmission electron microscopy (STEM) and field emission gun - scanning electron microscopy (FEG-SEM) showed the existence of nanoparticle clusters. X ray photoelectron spectroscopy (XPS) revealed the presence of silver in the sample surface region. The surface topography was studied by atomic force microscopy (AFM), while the surface composition uniformity was analyzed using phase imaging AFM. Optical characterization obtained by spectroscopic ellipsometry (SE) showed changes in refractive index, extinction coefficient and the optical band gap with the fluence of implanted ions.
{"title":"Structural and optical properties of HDPE implanted with medium fluences silver ions","authors":"M. Nenadovic, Danilo Kisić, M. Mirković, S. Nenadović, Ljiljana M. Kljajević","doi":"10.2298/sos2102187n","DOIUrl":"https://doi.org/10.2298/sos2102187n","url":null,"abstract":"The implantation of high-density polyethylene (HDPE) has been conducted using\u0000 Ag+ ions with energy of 60 keV, achieved fluences 1.5 and 10?1015 ions/cm2.\u0000 Transmission electron microscopy (STEM) and field emission gun - scanning\u0000 electron microscopy (FEG-SEM) showed the existence of nanoparticle clusters.\u0000 X ray photoelectron spectroscopy (XPS) revealed the presence of silver in\u0000 the sample surface region. The surface topography was studied by atomic\u0000 force microscopy (AFM), while the surface composition uniformity was\u0000 analyzed using phase imaging AFM. Optical characterization obtained by\u0000 spectroscopic ellipsometry (SE) showed changes in refractive index,\u0000 extinction coefficient and the optical band gap with the fluence of\u0000 implanted ions.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42390880","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. Gauna, Juan Martinez, M. S. Conconi, G. Suarez, N. Rendtorff
The effect of the TiO2 addition in the ceramic processing of dense zircon materials from zircon fine powders was established. The addition of TiO2 (5-10 wt%) permitted to obtain dense ceramics at lower temperatures (100-150 oC below), with comparable mechanical behavior. The thermochemical processes were described after a multi-technique experimental approach, which included a sintering analysis, powder X-Ray diffraction analysis (XRD), scanning electronic microscopy (SEM) and Vickers hardness of the polished dense obtained ceramics. After 1400 oC heating programs, the added TiO2 acts as a sintering aid with no important chemical reactions, and presented improved mechanical behavior in comparison with pure zircon ceramics. On the other side, in samples fired at 1500 oC, TiO2 partially (?50 %) reacts with zircon, forming ZrTiO4, while the formed SiO2 goes to the grain boundaries. Samples with 5 wt% TiO2 present better mechanical behavior than the ones with 10 wt%. The performed mechanical characterization indicates the merits of the material processed by this inexpensive processing route. Developed density, hardness (?10 GPa) and fracture toughness (?2 MPa.m-1/2) are comparable with the best figures reported.
{"title":"Effect of TiO2 in fine zircon sintering and properties","authors":"M. Gauna, Juan Martinez, M. S. Conconi, G. Suarez, N. Rendtorff","doi":"10.2298/sos2102267g","DOIUrl":"https://doi.org/10.2298/sos2102267g","url":null,"abstract":"The effect of the TiO2 addition in the ceramic processing of dense zircon\u0000 materials from zircon fine powders was established. The addition of TiO2\u0000 (5-10 wt%) permitted to obtain dense ceramics at lower temperatures (100-150\u0000 oC below), with comparable mechanical behavior. The thermochemical processes\u0000 were described after a multi-technique experimental approach, which included\u0000 a sintering analysis, powder X-Ray diffraction analysis (XRD), scanning\u0000 electronic microscopy (SEM) and Vickers hardness of the polished dense\u0000 obtained ceramics. After 1400 oC heating programs, the added TiO2 acts as a\u0000 sintering aid with no important chemical reactions, and presented improved\u0000 mechanical behavior in comparison with pure zircon ceramics. On the other\u0000 side, in samples fired at 1500 oC, TiO2 partially (?50 %) reacts with\u0000 zircon, forming ZrTiO4, while the formed SiO2 goes to the grain boundaries.\u0000 Samples with 5 wt% TiO2 present better mechanical behavior than the ones\u0000 with 10 wt%. The performed mechanical characterization indicates the merits\u0000 of the material processed by this inexpensive processing route. Developed\u0000 density, hardness (?10 GPa) and fracture toughness (?2 MPa.m-1/2) are\u0000 comparable with the best figures reported.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48080716","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}
Vesna Ribić, A. Rečnik, G. Dražič, M. Podlogar, Z. Branković, G. Branković
In our recent study (Ribic et al. 2020) we reported the structure of inversion boundaries (IBs) in Sb2O3-doped ZnO. Here, we focus on IBs that form in SnO2-doped ZnO. Using atomic resolution scanning transmission electron microscopy (STEM) methods we confirm that in SnO2-doped ZnO the IBs form in head-to-head configuration, where ZnO4 tetrahedra in both ZnO domains point towards the IB plane composed of a close-packed layer of octahedrally coordinated Sn and Zn atoms. The in-plane composition is driven by the local charge balance, following Pauling's principle of electroneutrality for ionic crystals, according to which the average oxidation state of cations is 3+. To satisfy this condition, the cation ratio in the IB-layer is Sn4+: Zn2+=1:1. This was confirmed by concentric electron probe analysis employing energy dispersive spectroscopy (EDS) showing that Sn atoms occupy 0.504 ? 0.039 of the IB layer, while the rest of the octahedral sites are occupied by Zn. IBs in SnO2-doped ZnO occur in the lowest energy, IB3 translation state with the cation sublattice expansion of ?IB(Zn-Zn) of +91 pm with corresponding O-sublattice contraction ?IB(O-O) of -46 pm. Based on quantitative HRTEM and HAADF-STEM analysis of in-plane ordering of Sn and Zn atoms, we identified two types of short-range distributions, (i) zigzag and (ii) stripe. Our density functional theory (DFT) calculations showed that the energy difference between the two arrangements is small (~6 meV) giving rise to their alternation within the octahedral IB layer. As a result, cation ordering intermittently changes its type and the direction to maximize intrinsic entropy of the IB layer driven by the in-plane electroneutrality and 6-fold symmetry restrictions. A long-range in-plane disorder, as shown by our work would enhance quantum well effect to phonon scattering, while Zn2+ located in the IB octahedral sites, would modify the bandgap, and enhance the in-plane conductivity and concentration of carriers. Keywords
{"title":"TEM and DFT study of basal-plane inversion boundaries in SnO2-doped ZnO","authors":"Vesna Ribić, A. Rečnik, G. Dražič, M. Podlogar, Z. Branković, G. Branković","doi":"10.2298/sos2102237r","DOIUrl":"https://doi.org/10.2298/sos2102237r","url":null,"abstract":"In our recent study (Ribic et al. 2020) we reported the structure of\u0000 inversion boundaries (IBs) in Sb2O3-doped ZnO. Here, we focus on IBs that\u0000 form in SnO2-doped ZnO. Using atomic resolution scanning transmission\u0000 electron microscopy (STEM) methods we confirm that in SnO2-doped ZnO the IBs\u0000 form in head-to-head configuration, where ZnO4 tetrahedra in both ZnO\u0000 domains point towards the IB plane composed of a close-packed layer of\u0000 octahedrally coordinated Sn and Zn atoms. The in-plane composition is driven\u0000 by the local charge balance, following Pauling's principle of\u0000 electroneutrality for ionic crystals, according to which the average\u0000 oxidation state of cations is 3+. To satisfy this condition, the cation\u0000 ratio in the IB-layer is Sn4+: Zn2+=1:1. This was confirmed by concentric\u0000 electron probe analysis employing energy dispersive spectroscopy (EDS)\u0000 showing that Sn atoms occupy 0.504 ? 0.039 of the IB layer, while the rest\u0000 of the octahedral sites are occupied by Zn. IBs in SnO2-doped ZnO occur in\u0000 the lowest energy, IB3 translation state with the cation sublattice\u0000 expansion of ?IB(Zn-Zn) of +91 pm with corresponding O-sublattice\u0000 contraction ?IB(O-O) of -46 pm. Based on quantitative HRTEM and HAADF-STEM\u0000 analysis of in-plane ordering of Sn and Zn atoms, we identified two types of\u0000 short-range distributions, (i) zigzag and (ii) stripe. Our density\u0000 functional theory (DFT) calculations showed that the energy difference\u0000 between the two arrangements is small (~6 meV) giving rise to their\u0000 alternation within the octahedral IB layer. As a result, cation ordering\u0000 intermittently changes its type and the direction to maximize intrinsic\u0000 entropy of the IB layer driven by the in-plane electroneutrality and 6-fold\u0000 symmetry restrictions. A long-range in-plane disorder, as shown by our work\u0000 would enhance quantum well effect to phonon scattering, while Zn2+ located\u0000 in the IB octahedral sites, would modify the bandgap, and enhance the\u0000 in-plane conductivity and concentration of carriers. Keywords","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42741237","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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