Nano-hematite (α-Fe2O3) and nano-cadmium ferrite (CdFe2O4) are prepared using template-assisted sol-gel method. The prepared samples are analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Mossbauer spectroscopy techniques for structural and microstructural studies. Nano-α-Fe2O3 with particle size ~60 nm is formed at 500°C, while nano-CdFe2O4 with smaller particle size (~40 nm) is formed at 600°C. It is found that with a simple sol-gel process we can prepare nano-CdFe2O4 with better conditions than other methods: pure phase at lower sintering temperature and time (economic point) and of course with a smaller particle size. So, based on the obtained experimental results, a proposed theoretical model is made to explain the link between the use of the sol-gel process and the formation of nano-CdFe2O4 as a pure phase at low temperature. This model is based on a simple magnetostatic interaction between the formed nuclei within the solution leading to the formation of the stable phase at low temperature.
{"title":"Preparation and Characterization of Nano-Cadmium Ferrite","authors":"S. M. Ismail, S. Labib, S. Attallah","doi":"10.1155/2013/526434","DOIUrl":"https://doi.org/10.1155/2013/526434","url":null,"abstract":"Nano-hematite (α-Fe2O3) and nano-cadmium ferrite (CdFe2O4) are prepared using template-assisted sol-gel method. The prepared samples are analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Mossbauer spectroscopy techniques for structural and microstructural studies. Nano-α-Fe2O3 with particle size ~60 nm is formed at 500°C, while nano-CdFe2O4 with smaller particle size (~40 nm) is formed at 600°C. It is found that with a simple sol-gel process we can prepare nano-CdFe2O4 with better conditions than other methods: pure phase at lower sintering temperature and time (economic point) and of course with a smaller particle size. So, based on the obtained experimental results, a proposed theoretical model is made to explain the link between the use of the sol-gel process and the formation of nano-CdFe2O4 as a pure phase at low temperature. This model is based on a simple magnetostatic interaction between the formed nuclei within the solution leading to the formation of the stable phase at low temperature.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"35 1","pages":"1-8"},"PeriodicalIF":16.9,"publicationDate":"2013-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81351575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gamma ray exposure buildup factor for some ceramics such as boron nitride (BN), magnesium diboride (MgB2), silicon carbide (SiC), titanium carbide (TiC) and ferrite (Fe3O4) has been computed using five parametric geometric progression (G.P.) fitting method in the energy range of 0.015 to 15.0 MeV, up to the penetration of 40 mean free path (mfp). The variation of exposure buildup factors for all the selected ceramics with incident photon energy, penetration depth, and chemical composition has been studied.
{"title":"Study of Gamma Ray Exposure Buildup Factor for Some Ceramics with Photon Energy, Penetration Depth and Chemical Composition","authors":"T. Singh, G. Kaur, Parjit S. Singh","doi":"10.1155/2013/721606","DOIUrl":"https://doi.org/10.1155/2013/721606","url":null,"abstract":"Gamma ray exposure buildup factor for some ceramics such as boron nitride (BN), magnesium diboride (MgB2), silicon carbide (SiC), titanium carbide (TiC) and ferrite (Fe3O4) has been computed using five parametric geometric progression (G.P.) fitting method in the energy range of 0.015 to 15.0 MeV, up to the penetration of 40 mean free path (mfp). The variation of exposure buildup factors for all the selected ceramics with incident photon energy, penetration depth, and chemical composition has been studied.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"2 1","pages":"1-6"},"PeriodicalIF":16.9,"publicationDate":"2013-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79189704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. F. Portella, A. Joukoski, J. B. Carmo, Camila Fernanda Novak Pinheiro de Freitas, Carlos Vicente Gomes Filho, Cinthya Hoppen
Industrial residues such as sludge from water treatment plants (Swtp) from centrifuged method; electrical porcelain residues (Pw); silica fume (Sf1 and Sf2); tire-rubber waste were evaluated in order to be used in concrete structures of electrical energy and environmental sectors, such as utility poles, crossarms, and reef balls technology. The results showed the necessity for evaluating different recycling concentrations in concrete, concomitantly to physicochemical tests allowing to diagnose natural and accelerated aging.
{"title":"The use of Waste Materials in Utility Poles, Crossarms, Paver, and Reef Balls Concrete Structures: Advantages and Care","authors":"K. F. Portella, A. Joukoski, J. B. Carmo, Camila Fernanda Novak Pinheiro de Freitas, Carlos Vicente Gomes Filho, Cinthya Hoppen","doi":"10.1155/2013/134169","DOIUrl":"https://doi.org/10.1155/2013/134169","url":null,"abstract":"Industrial residues such as sludge from water treatment plants (Swtp) from centrifuged method; electrical porcelain residues (Pw); silica fume (Sf1 and Sf2); tire-rubber waste were evaluated in order to be used in concrete structures of electrical energy and environmental sectors, such as utility poles, crossarms, and reef balls technology. The results showed the necessity for evaluating different recycling concentrations in concrete, concomitantly to physicochemical tests allowing to diagnose natural and accelerated aging.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"117 1","pages":"1-8"},"PeriodicalIF":16.9,"publicationDate":"2013-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87914035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Some recorded behaviours differences between chalcopyrite ternary oxide ceramics and telluride and sulphides are investigated in the framework of the recently proposed Lattice Compatibility Theory (LCT). Alterations have been evaluated in terms of Urbach tailing and atomic valence shell electrons orbital eigenvalues, which were calculated through several approximations. The aim of the study was mainly an attempt to explain the intriguing problem of difficulties of elaborating chalcopyrite ternary oxide ceramics (I-III-O2) at relatively low temperatures under conditions which allowed crystallization of ternary telluride and sulphides.
{"title":"The Lattice Compatibility Theory: Arguments for Recorded I-III-O2 Ternary Oxide Ceramics Instability at Low Temperatures beside Ternary Telluride and Sulphide Ceramics","authors":"K. Boubaker","doi":"10.1155/2013/734015","DOIUrl":"https://doi.org/10.1155/2013/734015","url":null,"abstract":"Some recorded behaviours differences between chalcopyrite ternary oxide ceramics and telluride and sulphides are investigated in the framework of the recently proposed Lattice Compatibility Theory (LCT). Alterations have been evaluated in terms of Urbach tailing and atomic valence shell electrons orbital eigenvalues, which were calculated through several approximations. The aim of the study was mainly an attempt to explain the intriguing problem of difficulties of elaborating chalcopyrite ternary oxide ceramics (I-III-O2) at relatively low temperatures under conditions which allowed crystallization of ternary telluride and sulphides.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"61 1","pages":"1-6"},"PeriodicalIF":16.9,"publicationDate":"2013-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78133664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An effort has been made to synthesize polycrystalline (abbreviated as BLNT) system with compositions x = 0, 0.02, and 0.04 by novel semiwet technique. Preparation of A-site oxides of BLNT for composition x = 0 was optimized using two precursor solutions such as ethylene glycol and citric acid. The XRD patterns revealed that the sample prepared by ethylene glycol precursor solution has single phase perovskite structure with a rhombohedral symmetry at RT as compared to the sample prepared by citric acid. Ethylene glycol precursor has been found to play a significant role in the crystallization, phase transitions, and electrical properties. The studies on structure, phase transitions, and dielectric properties for all the samples have been carried out over the temperature range from RT to 450°C at 100 kHz frequency. It has been observed that two phase transitions (i) ferroelectric to antiferroelectric and (ii) antiferroelectric to paraelectric occur in all the samples. All samples exhibit a modified Curie-Weiss law above Tc. A linear fitting of the modified Curie-Weiss law to the experimental data shows diffuse-type transition. The dielectric as well as ferroelectric properties of BLNT ceramics have been found to be improved with the substitution of La elements.
{"title":"Effect of Processing on Synthesis and Dielectric Behavior of Bismuth Sodium Titanate Ceramics","authors":"V. Pal, R. Dwivedi, O. P. Thakur","doi":"10.1155/2013/261914","DOIUrl":"https://doi.org/10.1155/2013/261914","url":null,"abstract":"An effort has been made to synthesize polycrystalline (abbreviated as BLNT) system with compositions x = 0, 0.02, and 0.04 by novel semiwet technique. Preparation of A-site oxides of BLNT for composition x = 0 was optimized using two precursor solutions such as ethylene glycol and citric acid. The XRD patterns revealed that the sample prepared by ethylene glycol precursor solution has single phase perovskite structure with a rhombohedral symmetry at RT as compared to the sample prepared by citric acid. Ethylene glycol precursor has been found to play a significant role in the crystallization, phase transitions, and electrical properties. The studies on structure, phase transitions, and dielectric properties for all the samples have been carried out over the temperature range from RT to 450°C at 100 kHz frequency. It has been observed that two phase transitions (i) ferroelectric to antiferroelectric and (ii) antiferroelectric to paraelectric occur in all the samples. All samples exhibit a modified Curie-Weiss law above Tc. A linear fitting of the modified Curie-Weiss law to the experimental data shows diffuse-type transition. The dielectric as well as ferroelectric properties of BLNT ceramics have been found to be improved with the substitution of La elements.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"85 1","pages":"1-6"},"PeriodicalIF":16.9,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83215954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ramanathan Papitha, M. B. Suresh, D. Das, Roy Johnson
Investigations were carried out, on the effect of addition of kaolinite (2Al2O3·3SiO2·2H2O) and talc (Mg3Si4O10(OH)2) in terms of bulk density, XRD phases, microstructure, as well as thermal and mechanical properties of the aluminium titanate (AT) ceramics. AT ceramics with additives have shown enhanced sinterability at 1550°C, achieving close to 99% of TD (theoretical density) in comparison to 87% TD, exhibited with pure AT samples sintered at 1600°C, and found to be in agreement with the microstructural observations. XRD phase analysis of samples with maximum densities resulted in pure AT phase with a shift in unit cell parameters suggesting the formation of solid solutions. TG-DSC study indicated a clear shift in AT formation temperature with talc addition. Sintered specimens exhibited significant reduction in linear thermal expansion values by 63% (0.4210−6/C, (30–1000°C)) with talc addition. Thermal hysteresis of talc-doped AT specimens showed a substantial increase in hysteresis area corresponding to enhanced microcrack densities which in turn was responsible to maintain the low expansion values. Microstructural evaluation revealed a sizable decrease in crack lengths and 200% increase in flexural strength with talc addition. Results are encouraging providing a stable formulation with substantially enhanced thermomechanical properties.
{"title":"Mineral-Oxide-Doped Aluminum Titanate Ceramics with Improved Thermomechanical Properties","authors":"Ramanathan Papitha, M. B. Suresh, D. Das, Roy Johnson","doi":"10.1155/2013/214974","DOIUrl":"https://doi.org/10.1155/2013/214974","url":null,"abstract":"Investigations were carried out, on the effect of addition of kaolinite (2Al2O3·3SiO2·2H2O) and talc (Mg3Si4O10(OH)2) in terms of bulk density, XRD phases, microstructure, as well as thermal and mechanical properties of the aluminium titanate (AT) ceramics. AT ceramics with additives have shown enhanced sinterability at 1550°C, achieving close to 99% of TD (theoretical density) in comparison to 87% TD, exhibited with pure AT samples sintered at 1600°C, and found to be in agreement with the microstructural observations. XRD phase analysis of samples with maximum densities resulted in pure AT phase with a shift in unit cell parameters suggesting the formation of solid solutions. TG-DSC study indicated a clear shift in AT formation temperature with talc addition. Sintered specimens exhibited significant reduction in linear thermal expansion values by 63% (0.4210−6/C, (30–1000°C)) with talc addition. Thermal hysteresis of talc-doped AT specimens showed a substantial increase in hysteresis area corresponding to enhanced microcrack densities which in turn was responsible to maintain the low expansion values. Microstructural evaluation revealed a sizable decrease in crack lengths and 200% increase in flexural strength with talc addition. Results are encouraging providing a stable formulation with substantially enhanced thermomechanical properties.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"99 1","pages":"1-9"},"PeriodicalIF":16.9,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85891885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. P. Reddy, W. Madhuri, M. Ramana, Il-Gon Kim, D. Yoo, N. R. Reddy, K. Kumar, D. Subbaiah, R. R. Reddy
NiCuZn ferrite with composition of (NCu0.10Zn0.60F) (where , 0.02, 0.04, 0.06, 0.08, and 0.10) was prepared by the conventional ceramic double sintering technique. The formation of single phase was confirmed by X-ray diffraction. The microstructural features were also studied by electronic microscopy and are reported. Initial permeability measurements on these samples were carried out in the temperature range of 30 to 300°C. The effect of external applied stress on the open magnetic circuit type coil with these ferrite cores was studied by applying uniaxial compressive stress parallel to the magnetizing direction and the change in the inductance was measured. The variation of inductance (ΔL/L)% increases up to certain applied compressive stress and there after it decreases, showing different stress sensitivities for different compositions of ferrites studied in the present work. The variation of ratio of inductance (ΔL/L)% with external applied compressive stress was examined. These results show that the Ni0.42Cu0.10Zn0.60Fe1.76O3.76 and Ni0.44Cu0.10Zn0.60Fe1.72O3.72 samples are found to be suitable for inductive stress sensor applications.
{"title":"Possibility of NiCuZn Ferrites Composition for Stress Sensor Applications","authors":"M. P. Reddy, W. Madhuri, M. Ramana, Il-Gon Kim, D. Yoo, N. R. Reddy, K. Kumar, D. Subbaiah, R. R. Reddy","doi":"10.1155/2013/901375","DOIUrl":"https://doi.org/10.1155/2013/901375","url":null,"abstract":"NiCuZn ferrite with composition of (NCu0.10Zn0.60F) (where , 0.02, 0.04, 0.06, 0.08, and 0.10) was prepared by the conventional ceramic double sintering technique. The formation of single phase was confirmed by X-ray diffraction. The microstructural features were also studied by electronic microscopy and are reported. Initial permeability measurements on these samples were carried out in the temperature range of 30 to 300°C. The effect of external applied stress on the open magnetic circuit type coil with these ferrite cores was studied by applying uniaxial compressive stress parallel to the magnetizing direction and the change in the inductance was measured. The variation of inductance (ΔL/L)% increases up to certain applied compressive stress and there after it decreases, showing different stress sensitivities for different compositions of ferrites studied in the present work. The variation of ratio of inductance (ΔL/L)% with external applied compressive stress was examined. These results show that the Ni0.42Cu0.10Zn0.60Fe1.76O3.76 and Ni0.44Cu0.10Zn0.60Fe1.72O3.72 samples are found to be suitable for inductive stress sensor applications.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"74 1","pages":"1-6"},"PeriodicalIF":16.9,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85818447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Computational material methods were used to predict and investigate electrical and structural properties of cerium oxide (CeO2). Density functional theory was used to obtain the optimized crystal structure and simulate the material’s electronic and elastic responses. Oxygen to oxygen nearest neighbor distance is 2.628 A, while oxygen to cerium distance is calculated to be 2.276 A. The conduction band has a prominent set of bands, which exists between 6 and 17 eV. An indirect energy gap (6.04 eV) exists between the valence and conduction bands. The independent elastic constants allow a mechanical assessment on the suitability of cubic cerium oxide as a substrate for advanced electronic devices. The calculated results of phonon dispersion curves are also given.
{"title":"Basic Elastic Properties Predictions of Cubic Cerium Oxide Using First-Principles Methods","authors":"J. Goldsby","doi":"10.1155/2013/323018","DOIUrl":"https://doi.org/10.1155/2013/323018","url":null,"abstract":"Computational material methods were used to predict and investigate electrical and structural properties of cerium oxide (CeO2). Density functional theory was used to obtain the optimized crystal structure and simulate the material’s electronic and elastic responses. Oxygen to oxygen nearest neighbor distance is 2.628 A, while oxygen to cerium distance is calculated to be 2.276 A. The conduction band has a prominent set of bands, which exists between 6 and 17 eV. An indirect energy gap (6.04 eV) exists between the valence and conduction bands. The independent elastic constants allow a mechanical assessment on the suitability of cubic cerium oxide as a substrate for advanced electronic devices. The calculated results of phonon dispersion curves are also given.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"GE-23 1","pages":"1-4"},"PeriodicalIF":16.9,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84615769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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