Fine reactive alumina powders have a significant impact on the properties of refractories at high temperatures. Except for the hydration of cement and in situ reactions, the performance of castables is also correlated with the sintering of reactive alumina. The characteristics of fine alumina powders produced by various manufacturers are quite different. This work aims to investigate the comprehensive influence of powder characteristics on the sintering behaviour of reactive alumina powders. Three types of commercial reactive alumina powders were selected for experiments. The linear shrinkage, bulk density, apparent porosity and microstructure of alumina compacts calcined at different temperatures were analysed. It was demonstrated that large specific surface area and higher SiO2 content had a positive effect on the densification of alumina compacts. The calculation based on the hypothetical composition of alumina grain boundary indicated that SiO2 mainly participated in the formation of liquid. Therefore, more liquid was generated at the grain boundary of alumina grains containing higher SiO2 content, which resulted in better sinterability of reactive alumina powders.
{"title":"Influence of powder characteristics on the sintering behaviour of reactive alumina powders","authors":"Hai Tang, Yingheng Shi, W. Yuan","doi":"10.2298/pac2201001t","DOIUrl":"https://doi.org/10.2298/pac2201001t","url":null,"abstract":"Fine reactive alumina powders have a significant impact on the properties of refractories at high temperatures. Except for the hydration of cement and in situ reactions, the performance of castables is also correlated with the sintering of reactive alumina. The characteristics of fine alumina powders produced by various manufacturers are quite different. This work aims to investigate the comprehensive influence of powder characteristics on the sintering behaviour of reactive alumina powders. Three types of commercial reactive alumina powders were selected for experiments. The linear shrinkage, bulk density, apparent porosity and microstructure of alumina compacts calcined at different temperatures were analysed. It was demonstrated that large specific surface area and higher SiO2 content had a positive effect on the densification of alumina compacts. The calculation based on the hypothetical composition of alumina grain boundary indicated that SiO2 mainly participated in the formation of liquid. Therefore, more liquid was generated at the grain boundary of alumina grains containing higher SiO2 content, which resulted in better sinterability of reactive alumina powders.","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":"68579424","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}
Hydrophobic and hydrophilic coatings have been widely studied because of their functions such as anticorrosion and self-cleaning. In this study two different TiO2 suspensions, obtained by dispersing of hydrophilic and hydrophobic TiO2 particles in ethanol, were used for preparation of titania coatings on stainless steel substrates by pulsed electrophoretic deposition (EPD). The resultant hydrophilic and hydrophobic rytile TiO2 coatings showed random orientation and are dense with no cracks. The thicknesses of the coatings obtained using hydrophilic and hydrophobic TiO2 particles were 22.5 and 20.1 ?m, respectively, whereas thier contact angles were 6.3? and 124.0?, respectively. The results show that hydrophilic and hydrophobic TiO2 coatings can be performed using pulsed EPD.
{"title":"Hydrophilic and hydrophobic TiO2 coatings by pulsed electrophoretic deposition","authors":"Hidetoshi Miyazaki, M. Yamane, Yu Mimaru","doi":"10.2298/pac2201083m","DOIUrl":"https://doi.org/10.2298/pac2201083m","url":null,"abstract":"Hydrophobic and hydrophilic coatings have been widely studied because of their functions such as anticorrosion and self-cleaning. In this study two different TiO2 suspensions, obtained by dispersing of hydrophilic and hydrophobic TiO2 particles in ethanol, were used for preparation of titania coatings on stainless steel substrates by pulsed electrophoretic deposition (EPD). The resultant hydrophilic and hydrophobic rytile TiO2 coatings showed random orientation and are dense with no cracks. The thicknesses of the coatings obtained using hydrophilic and hydrophobic TiO2 particles were 22.5 and 20.1 ?m, respectively, whereas thier contact angles were 6.3? and 124.0?, respectively. The results show that hydrophilic and hydrophobic TiO2 coatings can be performed using pulsed EPD.","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":"68580366","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}
P. Raju, P. Biswas, A. Khanra, Y. Rao, Roy Johnson
Pressure assisted casting of advanced ceramics is an emerging preparation technique as it permits using a colloidal slips in shaping under pressure. Application of pressure provides flexibility in forming of complex shapes in combination with high homogeneity, superior green density, strength and high productivity. Current study compares conventional slip casting (CSC), pressure slip casting (PSC) and cold isostatic pressing (CIP) used for preparation of alumina green bodies. Since particle size is a limitation in PSC process due to the defined pore size of the mould, the same starting alumina powder obtained by mixing of powders with two different average particle size (7 ?m and 1.43 ?m) in the proportion of 65:35 was employed in all three processes. Green densities of 65%TD at 35 bar in case of PSC and 66%TD at 1200 bar after CIP were obtained; however, density of the CSC samples was only 50%TD. Flexural strength and fractographic studies were carried out and correlated with the respective processes. The samples were also sintered at 1600 ?C to evaluate their sinterability.
{"title":"Investigations on colloidal and dry formed alumina parts under pressure and pressure-less conditions","authors":"P. Raju, P. Biswas, A. Khanra, Y. Rao, Roy Johnson","doi":"10.2298/pac2202160r","DOIUrl":"https://doi.org/10.2298/pac2202160r","url":null,"abstract":"Pressure assisted casting of advanced ceramics is an emerging preparation technique as it permits using a colloidal slips in shaping under pressure. Application of pressure provides flexibility in forming of complex shapes in combination with high homogeneity, superior green density, strength and high productivity. Current study compares conventional slip casting (CSC), pressure slip casting (PSC) and cold isostatic pressing (CIP) used for preparation of alumina green bodies. Since particle size is a limitation in PSC process due to the defined pore size of the mould, the same starting alumina powder obtained by mixing of powders with two different average particle size (7 ?m and 1.43 ?m) in the proportion of 65:35 was employed in all three processes. Green densities of 65%TD at 35 bar in case of PSC and 66%TD at 1200 bar after CIP were obtained; however, density of the CSC samples was only 50%TD. Flexural strength and fractographic studies were carried out and correlated with the respective processes. The samples were also sintered at 1600 ?C to evaluate their sinterability.","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":"68580561","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}
N. Amirthalingam, Sathishkumar Panchatcharam, T. Deivarajan, Manohar Paramasivam
Titanium reinforced hydroxyapatite preparation was attempted by using TiH2. The hydroxyapatite (HAp) was obtained from wet chemical facile method and was mixed with TiH2 (5 to 20 wt.%). The mixtures were shaped by pressing and samples were sintered at different temperatures from 900 to 1200?C. X-ray diffraction results showed that all the high temperature sintered samples with higher amount of TiH2 contain ?-tricalcium phosphate (?-TCP) and perovskite CaTiO3 as the major crystalline phases, while minor reaction products like ?-TCP and tetracalcium phosphate (TTCP) were also recorded for the various HAp-TiH2 composites. Microstructure evaluation was done by scanning electronmicroscopy which revealed the change in microstructure from needle-like to hexagonal grainy structure with increasing TiH2 content. Fourier transform infrared spectroscopy was done for functional groups analysis while density and porosity were also measured to analyse sintering ability of the composite samples.
{"title":"Effect of TiH2 on microstructure of hydroxyapatite sintered at various temperatures","authors":"N. Amirthalingam, Sathishkumar Panchatcharam, T. Deivarajan, Manohar Paramasivam","doi":"10.2298/pac2202125a","DOIUrl":"https://doi.org/10.2298/pac2202125a","url":null,"abstract":"Titanium reinforced hydroxyapatite preparation was attempted by using TiH2. The hydroxyapatite (HAp) was obtained from wet chemical facile method and was mixed with TiH2 (5 to 20 wt.%). The mixtures were shaped by pressing and samples were sintered at different temperatures from 900 to 1200?C. X-ray diffraction results showed that all the high temperature sintered samples with higher amount of TiH2 contain ?-tricalcium phosphate (?-TCP) and perovskite CaTiO3 as the major crystalline phases, while minor reaction products like ?-TCP and tetracalcium phosphate (TTCP) were also recorded for the various HAp-TiH2 composites. Microstructure evaluation was done by scanning electronmicroscopy which revealed the change in microstructure from needle-like to hexagonal grainy structure with increasing TiH2 content. Fourier transform infrared spectroscopy was done for functional groups analysis while density and porosity were also measured to analyse sintering ability of the composite samples.","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":"68580778","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}
Mayara dos Santos Amarante, Júlia Maria de Morais Santos, J. Machado, M. Lente, Vera Lúcia Othéro de Brito
In the present work, densification and microstructure evolution of cobalt ferrite (FCO), nickel-cobalt ferrite (FNICO) and BaTiO3 (TB) ceramics under different sintering conditions were investigated. Subsequently, layered ferrite-BaTiO3 samples were formed by uniaxial pressing of the corresponding ceramic powders. These green samples were sintered with two different sintering schedules, aiming to study the ferrite-BaTiO3 interfaces after sintering. The analyses were made at the cross section of the interfaces and at the interface surfaces after separation of the layers. The sintered layered samples were utilized to analyze sintering mismatch, diffusion at the interfaces and identification of some newly formed phases. EDS analysis across the TB-FCO interface showed evidences of diffusion. It was observed that the FNICO layers were detached from TB during sintering, but the same was not observed in the TB-FCO samples, although shrinkage mismatch resulted in some defects. XRD analyses suggested the presence of Ti2O at the TB-FCO interface and BaTiNiFe10O19 at the TB-FNICO interface as products of the reactions between the ferrites and BaTiO3.
{"title":"Sintering of layered ferrite-BaTiO3 ceramics: Analysis of interfaces and effects of shrinkage mismatch","authors":"Mayara dos Santos Amarante, Júlia Maria de Morais Santos, J. Machado, M. Lente, Vera Lúcia Othéro de Brito","doi":"10.2298/pac2202134a","DOIUrl":"https://doi.org/10.2298/pac2202134a","url":null,"abstract":"In the present work, densification and microstructure evolution of cobalt ferrite (FCO), nickel-cobalt ferrite (FNICO) and BaTiO3 (TB) ceramics under different sintering conditions were investigated. Subsequently, layered ferrite-BaTiO3 samples were formed by uniaxial pressing of the corresponding ceramic powders. These green samples were sintered with two different sintering schedules, aiming to study the ferrite-BaTiO3 interfaces after sintering. The analyses were made at the cross section of the interfaces and at the interface surfaces after separation of the layers. The sintered layered samples were utilized to analyze sintering mismatch, diffusion at the interfaces and identification of some newly formed phases. EDS analysis across the TB-FCO interface showed evidences of diffusion. It was observed that the FNICO layers were detached from TB during sintering, but the same was not observed in the TB-FCO samples, although shrinkage mismatch resulted in some defects. XRD analyses suggested the presence of Ti2O at the TB-FCO interface and BaTiNiFe10O19 at the TB-FNICO interface as products of the reactions between the ferrites and BaTiO3.","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":"68580823","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 work, high-entropy Lix(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO (x = 0, 0.1, 0.2, 0.3, 0.4) ceramics with rocksalt structure were synthesized via simple sol-gel method and sintered at 1000?C. The crystal structure, crosssection micromorphology, conductivity, electronic conductivity and electrochemical stability of the sintered Lix(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO ceramics were investigated by X-ray diffraction, SEM, AC-impedance, DC-polarization and cyclic voltammetry, respectively. The Lix(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO ceramics present single rock-salt structure and no impurities were detected. The Li0.3(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)0.85O (x = 0.3) sample has the highest conductivity of 1.46 ? 10?5 S/cm at 30?C, with an activation energy of 0.334 eV. Conductivity of the (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O ceramics is enhanced by about four orders of magnitude with the partial substitution of (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2) by lithium. The electronic conductivity of the Li0.3(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)0.85O ceramics is much lower than its ionic conductivity, which suggests that Li0.3(MgCoNiCuZn)0.85O can be treated as ionic conductor. The Li0.3(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)0.85O sample is electrochemically stable between 1.23 and 4.7 V.
{"title":"Conductivity and electrochemical stability of Li+ substituted high-entropy Lix(mM0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO ceramics","authors":"Yazhou Kong, Guang Hu, Kailong Zhang, Weiwei Hu","doi":"10.2298/pac2203201k","DOIUrl":"https://doi.org/10.2298/pac2203201k","url":null,"abstract":"In this work, high-entropy Lix(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO (x = 0, 0.1, 0.2, 0.3, 0.4) ceramics with rocksalt structure were synthesized via simple sol-gel method and sintered at 1000?C. The crystal structure, crosssection micromorphology, conductivity, electronic conductivity and electrochemical stability of the sintered Lix(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO ceramics were investigated by X-ray diffraction, SEM, AC-impedance, DC-polarization and cyclic voltammetry, respectively. The Lix(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)1-0.5xO ceramics present single rock-salt structure and no impurities were detected. The Li0.3(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)0.85O (x = 0.3) sample has the highest conductivity of 1.46 ? 10?5 S/cm at 30?C, with an activation energy of 0.334 eV. Conductivity of the (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O ceramics is enhanced by about four orders of magnitude with the partial substitution of (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2) by lithium. The electronic conductivity of the Li0.3(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)0.85O ceramics is much lower than its ionic conductivity, which suggests that Li0.3(MgCoNiCuZn)0.85O can be treated as ionic conductor. The Li0.3(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)0.85O sample is electrochemically stable between 1.23 and 4.7 V.","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":"68580879","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 reports on the production of chitosan-based composite scaffolds reinforced with hydroxyapatite (HA) powders prepared with cerium oxide (CeO2) with various concentrations (10, 20, 30 wt.%). Besides, the effect of CeO2 additive on the microstructural,mechanical and bioactivity properties of the composite scaffolds was investigated. The CeO2 reinforced HA powders were synthesized having homogenous particle distribution via spray drying process. The synthesized powders and the produced scaffolds were examined using different characterization methods. From the results, it can be seen that the scaffolds were significantly affected by amount of CeO2 additive. An increase in the compressive strength is observed as the amount of CeO2 additive rises. Furthermore, the composite scaffolds possessed a high mineralization ability of apatite in simulated body fluid (SBF). These observations related to the composite scaffolds have considerable potency for application in bone tissue engineering.
{"title":"Incorporation of cerium oxide into hydroxyapatite/chitosan composite scaffolds for bone repair","authors":"Büşra Mutlu, Sena Çaylak, Şeyma Duman","doi":"10.2298/pac2203207m","DOIUrl":"https://doi.org/10.2298/pac2203207m","url":null,"abstract":"This study reports on the production of chitosan-based composite scaffolds reinforced with hydroxyapatite (HA) powders prepared with cerium oxide (CeO2) with various concentrations (10, 20, 30 wt.%). Besides, the effect of CeO2 additive on the microstructural,mechanical and bioactivity properties of the composite scaffolds was investigated. The CeO2 reinforced HA powders were synthesized having homogenous particle distribution via spray drying process. The synthesized powders and the produced scaffolds were examined using different characterization methods. From the results, it can be seen that the scaffolds were significantly affected by amount of CeO2 additive. An increase in the compressive strength is observed as the amount of CeO2 additive rises. Furthermore, the composite scaffolds possessed a high mineralization ability of apatite in simulated body fluid (SBF). These observations related to the composite scaffolds have considerable potency for application in bone tissue engineering.","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":"68580998","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 paper reports the interdisciplinary approach of simultaneous use of a stereological method, namely the five parameter analysis (FPA) method and the grain boundary character distribution (GBCD) in cemented carbides. There are six major aspects: i) the background and motivations of the interdisciplinary approach, ii) the principle of the FPA method, iii) orientation texture of boundary planes with specific misorientations via ?(?g, n) mode in cemented carbide, iv) orientation texture of habit planes regardless of misorientations via ?(n) mode in cemented carbide, v) application of the FPA method to serial cemented carbide samples and vi) boundary sort methods before using the FPA method. The work aims at presenting beneficial reference for studying structural and distribution features of special coincidence site lattice (CSL) boundaries in a statistical manner, and in turn increasing the knowledge about the structure-property relationship in cemented carbides.
{"title":"Characterization of grain boundary character distribution in cemented carbides via a stereological method","authors":"Xiaokun Yuan, Y. Ji","doi":"10.2298/pac2204341y","DOIUrl":"https://doi.org/10.2298/pac2204341y","url":null,"abstract":"This paper reports the interdisciplinary approach of simultaneous use of a stereological method, namely the five parameter analysis (FPA) method and the grain boundary character distribution (GBCD) in cemented carbides. There are six major aspects: i) the background and motivations of the interdisciplinary approach, ii) the principle of the FPA method, iii) orientation texture of boundary planes with specific misorientations via ?(?g, n) mode in cemented carbide, iv) orientation texture of habit planes regardless of misorientations via ?(n) mode in cemented carbide, v) application of the FPA method to serial cemented carbide samples and vi) boundary sort methods before using the FPA method. The work aims at presenting beneficial reference for studying structural and distribution features of special coincidence site lattice (CSL) boundaries in a statistical manner, and in turn increasing the knowledge about the structure-property relationship in cemented carbides.","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":"68581987","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}
T. Nguyen, A. Nguyen, V. Mittova, H. Chau, T. Nguyen, I. Mittova, X. Bui
A series of Nd1-xCdxFeO3 (x = 0.1, 0.2 and 0.3) nanoparticles were successfully synthesized from Nd(III), Cd(II) and Fe(III) nitrates by a simple co-precipitation method in boiling water with a 5% sodium hydroxide aqueous solution (without any surfactants) and annealed at 700, 850 and 950?C for 1 h. SEM and TEM analyses showed particle sizes in the range of 50-70 nm. According to XRD the average crystallite size increased with the annealing temperature, but decreased when the cadmium concentration increased. As the annealing temperature was raised from 700 to 950?C, the magnetic properties, such as coercivity (Hc), remanent magnetization (Mr) and saturation magnetization (Ms), of the Nd0.8Cd0.2FeO3 sample also increased. In general, the Hc, Mr and Ms values increased with the degree of cadmium doping. The synthesized Nd1-xCdxFeO3 nanopowders havemuch larger coercivity values than some other rare-earth perovskites, such as Nd1-xSrxFeO3, NdFe1-xCoxO3, LaFe1-xTixO3, YFe1-xNixO3, Y1-xCdxFeO3, La1-xCdxFeO3 or Bi1-xCdxFeO3. The high Hc value (1916.52-4833.41Oe) of the synthesized Nd1-xCdxFeO3 nanopowders enables their use for permanent magnets or magnetic recording on hard disks and tapes.
{"title":"Effect of annealing temperature and cadmium doping on structure and magnetic properties of neodymium orthoferrite nanoparticles synthesized by a simple co-precipitation method","authors":"T. Nguyen, A. Nguyen, V. Mittova, H. Chau, T. Nguyen, I. Mittova, X. Bui","doi":"10.2298/pac2204321n","DOIUrl":"https://doi.org/10.2298/pac2204321n","url":null,"abstract":"A series of Nd1-xCdxFeO3 (x = 0.1, 0.2 and 0.3) nanoparticles were successfully synthesized from Nd(III), Cd(II) and Fe(III) nitrates by a simple co-precipitation method in boiling water with a 5% sodium hydroxide aqueous solution (without any surfactants) and annealed at 700, 850 and 950?C for 1 h. SEM and TEM analyses showed particle sizes in the range of 50-70 nm. According to XRD the average crystallite size increased with the annealing temperature, but decreased when the cadmium concentration increased. As the annealing temperature was raised from 700 to 950?C, the magnetic properties, such as coercivity (Hc), remanent magnetization (Mr) and saturation magnetization (Ms), of the Nd0.8Cd0.2FeO3 sample also increased. In general, the Hc, Mr and Ms values increased with the degree of cadmium doping. The synthesized Nd1-xCdxFeO3 nanopowders havemuch larger coercivity values than some other rare-earth perovskites, such as Nd1-xSrxFeO3, NdFe1-xCoxO3, LaFe1-xTixO3, YFe1-xNixO3, Y1-xCdxFeO3, La1-xCdxFeO3 or Bi1-xCdxFeO3. The high Hc value (1916.52-4833.41Oe) of the synthesized Nd1-xCdxFeO3 nanopowders enables their use for permanent magnets or magnetic recording on hard disks and tapes.","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":"68582316","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}
Rauany Lopes, R. Furlan, W. Correr, Lísias P. Novo, L. Montrezor, E. Pecoraro, E. Trovatti
Homologues and xenogenous bones are currently the most used grafts in dentistry because of their performance. However, some inherent disadvantages of these materials have not yet been overcome, such as the lack of biological properties to improve the new bone formation in situ and the long remodeling time. The main aim of this work was to improve the performance of the commercial bone-based grafts and study its properties in vitro. For this purpose, rat bone was combined with bioglass, a synthetic biomaterial that displays high degradation kinetics and bioactivity properties, endowed with biological properties. The sol-gel method was used for 45S5 bioglass (45S5) synthesis, using TEOS and water soluble salts as starting materials. 45S5 was then associated with the rat bone, generating the new graft. FTIR results indicated the hydroxyapatite formation after the bioactivity tests. SEM and bioactivity results were used to assess the evolution of the graft. The bioactivity tests showed that after 30 days the mass gain of about 30 wt.% was due to the deposition of hydroxyapatite crystals at the surface of the grafts, suggesting the potential properties of this new graft for application in implantology.
{"title":"Bone-bioglass graft - an alternative to improve the osseointegration","authors":"Rauany Lopes, R. Furlan, W. Correr, Lísias P. Novo, L. Montrezor, E. Pecoraro, E. Trovatti","doi":"10.2298/pac2203230l","DOIUrl":"https://doi.org/10.2298/pac2203230l","url":null,"abstract":"Homologues and xenogenous bones are currently the most used grafts in dentistry because of their performance. However, some inherent disadvantages of these materials have not yet been overcome, such as the lack of biological properties to improve the new bone formation in situ and the long remodeling time. The main aim of this work was to improve the performance of the commercial bone-based grafts and study its properties in vitro. For this purpose, rat bone was combined with bioglass, a synthetic biomaterial that displays high degradation kinetics and bioactivity properties, endowed with biological properties. The sol-gel method was used for 45S5 bioglass (45S5) synthesis, using TEOS and water soluble salts as starting materials. 45S5 was then associated with the rat bone, generating the new graft. FTIR results indicated the hydroxyapatite formation after the bioactivity tests. SEM and bioactivity results were used to assess the evolution of the graft. The bioactivity tests showed that after 30 days the mass gain of about 30 wt.% was due to the deposition of hydroxyapatite crystals at the surface of the grafts, suggesting the potential properties of this new graft for application in implantology.","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":"68581185","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：