Pub Date : 2012-04-25DOI: 10.1002/9781118407899.CH23
M. Cole, W. Nothwang, R. Geyer
This study demonstrates that large area affordable silicon substrates can be utilized in phase shifter devices if a "microwave friendly passive buffer layer is sandwiched between the silicon substrate and the low loss active Ba 1-x Sr x TiO 3 (BST) based thin film. In this heterostructure configuration there will be negligible attenuation of the microwave energy by the substrate. In our approach, metalorganic solution deposition (MOSD) fabricated Ta 2 O 5 was employed as a buffer layer film to promote the integration of BST with affordable large area silicon substrates. In addition, the buffer layer material was designed to promote a tensile stress in the active thin film, such that the tunability of the BST-based coplanar device was enhanced to levels comparable to that of a varactor device design. The optimized Ta 2 O 5 based thin film possessed excellent material properties, namely, an enhanced dielectric constant (e r =45.6), low dielectric loss (tan δ=0.006), high film resistivity (p=10 12 Ω-cm at E=1 MV/cm), excellent temperature stability (TCK of 52 ppm/°C), and excellent bias stability of capacitance (-1.41% at 1 MV/cm). The integration of the BST/Ta 2 O 5 bilayer heterostructure on silicon substrates was demonstrated via a dual anneal process protocol. The defect free, structurally abrupt BST/Ta 2 O 5 and Ta 2 O 5 -silicon substrate interfaces; combined with the smooth, uniform and defect free surface morphology of the dual anneal fabricated heterostructure suggests this process protocol to be an excellent method for achieving successful monolithic integration of BST with affordable silicon substrates in a coplanar device design.
该研究表明，如果在硅衬底和低损耗的ba1 -x Sr x tio3 (BST)薄膜之间夹上一层“微波友好”无源缓冲层，则可以将大面积经济实惠的硅衬底用于移相器器件。在这种异质结构构型中，衬底对微波能量的衰减可以忽略不计。在我们的方法中，采用金属有机溶液沉积(MOSD)制备的ta2o5作为缓冲层膜，以促进BST与廉价的大面积硅衬底的集成。此外，缓冲层材料被设计为促进活性薄膜中的拉伸应力，从而使基于bst的共面器件的可调性提高到与变容管器件设计相当的水平。优化后的ta2o5基薄膜具有优异的材料性能，即介电常数提高(e r =45.6)，介电损耗低(tan δ=0.006)，薄膜电阻率高(e =1 MV/cm时p=10 12 Ω-cm)，温度稳定性好(TCK为52 ppm/°C)，电容偏置稳定性好(1 MV/cm时-1.41%)。通过双退火工艺证明了BST/ ta2o5双层异质结构在硅衬底上的集成。无缺陷、结构突变的BST/ ta2o5和ta2o5 -硅衬底界面;结合双退火异质结构的光滑、均匀和无缺陷的表面形貌，表明该工艺方案是在共面器件设计中实现BST与价格合理的硅衬底的成功单片集成的绝佳方法。
{"title":"Monolithic Integration of Nonlinear BA1‐xSRxTIO3 Thin Films with Affordable Silicon Substrates for Frequency Agile Microwave Device Applications","authors":"M. Cole, W. Nothwang, R. Geyer","doi":"10.1002/9781118407899.CH23","DOIUrl":"https://doi.org/10.1002/9781118407899.CH23","url":null,"abstract":"This study demonstrates that large area affordable silicon substrates can be utilized in phase shifter devices if a \"microwave friendly passive buffer layer is sandwiched between the silicon substrate and the low loss active Ba 1-x Sr x TiO 3 (BST) based thin film. In this heterostructure configuration there will be negligible attenuation of the microwave energy by the substrate. In our approach, metalorganic solution deposition (MOSD) fabricated Ta 2 O 5 was employed as a buffer layer film to promote the integration of BST with affordable large area silicon substrates. In addition, the buffer layer material was designed to promote a tensile stress in the active thin film, such that the tunability of the BST-based coplanar device was enhanced to levels comparable to that of a varactor device design. The optimized Ta 2 O 5 based thin film possessed excellent material properties, namely, an enhanced dielectric constant (e r =45.6), low dielectric loss (tan δ=0.006), high film resistivity (p=10 12 Ω-cm at E=1 MV/cm), excellent temperature stability (TCK of 52 ppm/°C), and excellent bias stability of capacitance (-1.41% at 1 MV/cm). The integration of the BST/Ta 2 O 5 bilayer heterostructure on silicon substrates was demonstrated via a dual anneal process protocol. The defect free, structurally abrupt BST/Ta 2 O 5 and Ta 2 O 5 -silicon substrate interfaces; combined with the smooth, uniform and defect free surface morphology of the dual anneal fabricated heterostructure suggests this process protocol to be an excellent method for achieving successful monolithic integration of BST with affordable silicon substrates in a coplanar device design.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"41 1","pages":"215-226"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88550129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118407844.CH9
N. Bansal, Dongming Zhu
10-mol% yttria-stabilized zirconia (10YSZ) - alumina composites containing 0-30 mol% alumina were fabricated by hot pressing at 1500 °C in vacuum. Thermal conductivity of the composites, determined at various temperatures using a steady-state laser heat flux technique, increased with increase in alumina content. Composites containing 0, 5, and 10-mol% alumina did not show any change in thermal conductivity with temperature. However, those containing 20 and 30-mol% alumina showed a decrease in thermal conductivity with increase in temperature. The measured values of thermal conductivity were in good agreement with those calculated from the Maxwell-Eucken model where one phase is uniformly dispersed within a second major continuous phase.
{"title":"High‐Emperature Thermal Conductivity of Alumina‐Reinforced Zirconia Composites","authors":"N. Bansal, Dongming Zhu","doi":"10.1002/9781118407844.CH9","DOIUrl":"https://doi.org/10.1002/9781118407844.CH9","url":null,"abstract":"10-mol% yttria-stabilized zirconia (10YSZ) - alumina composites containing 0-30 mol% alumina were fabricated by hot pressing at 1500 °C in vacuum. Thermal conductivity of the composites, determined at various temperatures using a steady-state laser heat flux technique, increased with increase in alumina content. Composites containing 0, 5, and 10-mol% alumina did not show any change in thermal conductivity with temperature. However, those containing 20 and 30-mol% alumina showed a decrease in thermal conductivity with increase in temperature. The measured values of thermal conductivity were in good agreement with those calculated from the Maxwell-Eucken model where one phase is uniformly dispersed within a second major continuous phase.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"70 1","pages":"93-105"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87213958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118407158.CH13
A. Jayatissa, T. Gupta
{"title":"Fine‐Grain Nanocrystalline Tungsten Oxide Films for Gas Sensor Applications","authors":"A. Jayatissa, T. Gupta","doi":"10.1002/9781118407158.CH13","DOIUrl":"https://doi.org/10.1002/9781118407158.CH13","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"8 1","pages":"119-124"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81957829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118408162.CH3
Y. Imanaka, J. Akedo
Embedding various passive components, such as capacitors, filters, and inductors, in one circuit board, effectively achieves miniaturization, cost reduction, and higher performance in RF wireless communication products. Much R&D into embedded passives has been conducted using different circuit board technologies. However, no circuit boards developed to date satisfy all [of the requirements that is required of them. We propose a resin built-up circuit board that embeds ceramic film with passive functions to achieve low-cost RF modules in the next generation. These circuit boards make it possible to simultaneously obtain a fine pattern for miniaturization, improved performance, such as low transmission loss and high capacitance density, and cost reduction. The key required to achieve such a circuit is ceramic deposition. Our unique aerosol deposition (AD) method can provide passive ceramic elements embedded in the resin substrate. The film is formed by accelerated ceramic nano-particle aerosol bombardment. Many kinds of ceramics can be deposited on a substrate at room temperature. We present a novel AD approach to fabricating embedded capacitors on resin FR-4 substrates and the experimental results. We also discuss the correlation between the microstructure and dielectric properties of AD dielectric films deposited under various conditions. We confirmed that dense BaTiO 3 dielectric films with a dielectric constant of 400 could be formed on resin substrates at RT. Embedded capacitors on an FR-4 substrate, fabricated as a prototype with this AD film, had a capacitance density of 300 nF/cm 2 .
{"title":"Embedded Ceramic Passive on FR‐4 Using Aerosol Deposition","authors":"Y. Imanaka, J. Akedo","doi":"10.1002/9781118408162.CH3","DOIUrl":"https://doi.org/10.1002/9781118408162.CH3","url":null,"abstract":"Embedding various passive components, such as capacitors, filters, and inductors, in one circuit board, effectively achieves miniaturization, cost reduction, and higher performance in RF wireless communication products. Much R&D into embedded passives has been conducted using different circuit board technologies. However, no circuit boards developed to date satisfy all [of the requirements that is required of them. We propose a resin built-up circuit board that embeds ceramic film with passive functions to achieve low-cost RF modules in the next generation. These circuit boards make it possible to simultaneously obtain a fine pattern for miniaturization, improved performance, such as low transmission loss and high capacitance density, and cost reduction. The key required to achieve such a circuit is ceramic deposition. Our unique aerosol deposition (AD) method can provide passive ceramic elements embedded in the resin substrate. The film is formed by accelerated ceramic nano-particle aerosol bombardment. Many kinds of ceramics can be deposited on a substrate at room temperature. We present a novel AD approach to fabricating embedded capacitors on resin FR-4 substrates and the experimental results. We also discuss the correlation between the microstructure and dielectric properties of AD dielectric films deposited under various conditions. We confirmed that dense BaTiO 3 dielectric films with a dielectric constant of 400 could be formed on resin substrates at RT. Embedded capacitors on an FR-4 substrate, fabricated as a prototype with this AD film, had a capacitance density of 300 nF/cm 2 .","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"70 1","pages":"27-38"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85367789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118408162.CH12
B. Bender, M. Pan
A series of lead magnesium niobate-lead titanate (PMN-PT) relaxor ferroelectrics have been produced via attrition milling and the columbite precursor method. These were synthesized in order to study the effect of La-doping and Ta-replacement of Nb on PMN-PT ceramics. La-doping led to a decrease in K max (maximum permittivity), T max (temperature of maximum permittivity), and average grain size. With increasing La-doping levels the PMN-PT ceramic exhibited relaxor-ferroelectric-like behavior as its dielectric constant spectrum became more diffuse. Ta replacement of Nb in PMN-PT ceramics led to PMTa-PT (lead magnesium tantalate-lead titanate) ceramics whose overall dielectric constant spectra were similar to that of the PMN-PT. B-site precursor processing, columbite precursor processing, and conventional mixed-oxide processing all yielded monophasic perovskite PMTa-PT ceramics after sintering at 1200°C.
{"title":"The Effect of Processing, Tantalum‐Replacement, and Lanthanumdoping on the Dielectric Properties of Lead Magnesium Niobate‐Lead Titanate Ceramics","authors":"B. Bender, M. Pan","doi":"10.1002/9781118408162.CH12","DOIUrl":"https://doi.org/10.1002/9781118408162.CH12","url":null,"abstract":"A series of lead magnesium niobate-lead titanate (PMN-PT) relaxor ferroelectrics have been produced via attrition milling and the columbite precursor method. These were synthesized in order to study the effect of La-doping and Ta-replacement of Nb on PMN-PT ceramics. La-doping led to a decrease in K max (maximum permittivity), T max (temperature of maximum permittivity), and average grain size. With increasing La-doping levels the PMN-PT ceramic exhibited relaxor-ferroelectric-like behavior as its dielectric constant spectrum became more diffuse. Ta replacement of Nb in PMN-PT ceramics led to PMTa-PT (lead magnesium tantalate-lead titanate) ceramics whose overall dielectric constant spectra were similar to that of the PMN-PT. B-site precursor processing, columbite precursor processing, and conventional mixed-oxide processing all yielded monophasic perovskite PMTa-PT ceramics after sintering at 1200°C.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"15 1","pages":"107-119"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89428225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118408353.CH9
M. Gordon, Jonathan L. Bell, W. Kriven
{"title":"Comparison of Naturally and Synthetically‐Derived, Potassiumbased Geopolymers","authors":"M. Gordon, Jonathan L. Bell, W. Kriven","doi":"10.1002/9781118408353.CH9","DOIUrl":"https://doi.org/10.1002/9781118408353.CH9","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"4 1","pages":"95-106"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89232537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118407899.CH19
M. Datta, J. Y. Kim, P. Kumta
A novel complexation based sol-gel process has been developed to synthesize Pt-50at.% Ru based anode catalysts possessing high specific surface area with good catalytic activity. A homogeneous amorphous gel was successfully synthesized by complexing platinum(II) acetylacetonate and ruthenium(III) acetylacetonate with tetramethylammonium hydroxide (TMAH) used as a complexing agent. Phase pure Pt(Ru) solid solution of nominal composition Pt-50at.% Ru, possessing high specific surface area (∼75m 2 /g-140m 2 /g) were successfully produced by controlled removal of carbonaceous species generated from the as-prepared precursor. The controlled removal of carbon related species has been successfully performed by controlled thermal treatment of the precursor using controlled oxidizing atmospheres such as 1% O 2 balanced with ultrahigh purity (UHP) argon. It has been identified that the nanocrystalline Pt(Ru) solid solution of nominal composition Pt-50at.% Ru possessing good chemical homogeneity with less amount of non-conducting carbon reveals an excellent catalytic activity, demonstrating the potential of the novel sol-gel process for synthesizing high-performance catalysts for direct methanol fuel cells.
{"title":"Novel Sol‐Gel Synthesis and Characterization of High‐Surfacearea Pt‐Ru Catalysts as Anodes for Direct Methanol Fuel Cells","authors":"M. Datta, J. Y. Kim, P. Kumta","doi":"10.1002/9781118407899.CH19","DOIUrl":"https://doi.org/10.1002/9781118407899.CH19","url":null,"abstract":"A novel complexation based sol-gel process has been developed to synthesize Pt-50at.% Ru based anode catalysts possessing high specific surface area with good catalytic activity. A homogeneous amorphous gel was successfully synthesized by complexing platinum(II) acetylacetonate and ruthenium(III) acetylacetonate with tetramethylammonium hydroxide (TMAH) used as a complexing agent. Phase pure Pt(Ru) solid solution of nominal composition Pt-50at.% Ru, possessing high specific surface area (∼75m 2 /g-140m 2 /g) were successfully produced by controlled removal of carbonaceous species generated from the as-prepared precursor. The controlled removal of carbon related species has been successfully performed by controlled thermal treatment of the precursor using controlled oxidizing atmospheres such as 1% O 2 balanced with ultrahigh purity (UHP) argon. It has been identified that the nanocrystalline Pt(Ru) solid solution of nominal composition Pt-50at.% Ru possessing good chemical homogeneity with less amount of non-conducting carbon reveals an excellent catalytic activity, demonstrating the potential of the novel sol-gel process for synthesizing high-performance catalysts for direct methanol fuel cells.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"15 5-6 1","pages":"165-172"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78251113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118408186.CH13
L. Živković, V. Mitić, V. Paunovic, L. Vracar, B. Stojanovic, K. Peron, M. A. Zagete
{"title":"The Synergistic Effects of Nb/Mn and Sb/Mn on the Microstructure and Electrical Characteristics of BaTiO3 Based Ceramics","authors":"L. Živković, V. Mitić, V. Paunovic, L. Vracar, B. Stojanovic, K. Peron, M. A. Zagete","doi":"10.1002/9781118408186.CH13","DOIUrl":"https://doi.org/10.1002/9781118408186.CH13","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"224 1","pages":"117-125"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75313117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118408391.CH11
Y. Blum, S. Young, D. Hui
MB2/SiC and MB 2 /MC/SiC composites (M = Hf or Zr) are materials of choice for ultrahigh-temperature applications, primarily in aerospace designs. Conventionally, they are processed by hot pressing at very high temperature (1900 to 2300°C). This study continues the evaluation of "low-temperature" reactions (i.e., below 1500°C) between metallic Hf and various B- and C-containing reagents leading to the formation of hafnium boride and carbide phases. Such reactions may allow the formation of structures and coatings made of HfB 2 /SiC and HfB 2 /HfC/SiC to be processed under pressureless or low-pressure conditions at convenient processing temperatures. In an earlier study, large Hf grains were found to disappear during reactions between loosely mixed (i.e., not compacted by pressing) reactant powders, leading to the assumption that Hf melts during the exothermic reaction. Such local melting would accelerate the remaining reaction by increasing the contact interface area between the Hf and the B and C donors. Reactions between loosely spread powders of one type on top of substrates made of a material capable of forming either HfB 2 or HfC phases have been evaluated after heating at 1500°C in a conventional tube furnace under argon at atmospheric pressure. The study focused on forming a molten phase, although all the reactants studied have melting points above 2200°. The microstructure and phase evolution in the reactions between B, B 4 C, BN, and C powders with Hf thin plates, and inversely, between Hf metal powder and B, BN, B 4 C, and C surfaces at 1500°C, are evaluated and discussed.
{"title":"Chemical Reactivity: In Search of Better Processing of HfB2/SiC UHTC Composites","authors":"Y. Blum, S. Young, D. Hui","doi":"10.1002/9781118408391.CH11","DOIUrl":"https://doi.org/10.1002/9781118408391.CH11","url":null,"abstract":"MB2/SiC and MB 2 /MC/SiC composites (M = Hf or Zr) are materials of choice for ultrahigh-temperature applications, primarily in aerospace designs. Conventionally, they are processed by hot pressing at very high temperature (1900 to 2300°C). This study continues the evaluation of \"low-temperature\" reactions (i.e., below 1500°C) between metallic Hf and various B- and C-containing reagents leading to the formation of hafnium boride and carbide phases. Such reactions may allow the formation of structures and coatings made of HfB 2 /SiC and HfB 2 /HfC/SiC to be processed under pressureless or low-pressure conditions at convenient processing temperatures. In an earlier study, large Hf grains were found to disappear during reactions between loosely mixed (i.e., not compacted by pressing) reactant powders, leading to the assumption that Hf melts during the exothermic reaction. Such local melting would accelerate the remaining reaction by increasing the contact interface area between the Hf and the B and C donors. Reactions between loosely spread powders of one type on top of substrates made of a material capable of forming either HfB 2 or HfC phases have been evaluated after heating at 1500°C in a conventional tube furnace under argon at atmospheric pressure. The study focused on forming a molten phase, although all the reactants studied have melting points above 2200°. The microstructure and phase evolution in the reactions between B, B 4 C, BN, and C powders with Hf thin plates, and inversely, between Hf metal powder and B, BN, B 4 C, and C surfaces at 1500°C, are evaluated and discussed.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"116 1","pages":"103-114"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79237736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-25DOI: 10.1002/9781118407950.CH22
Hong Zhao, I. Muller, I. Pegg
In some vitrification processes, the nuclear waste is first mixed with glass-forming additives to form an intermediate aqueous slurry before being processed through a melter at high temperature (typically 1100-1200°C) to form a glass of the desired composition and properties. The rheological characteristics of such an intermediate melter feed slurry are important for the mixing and transport of the feed slurry to the melter and also in the spreading of the slurry on the surface of the glass melt. In this paper, the effects of aging and temperature on the rheological properties of melter feed slurries have been investigated for various high-sodium waste streams. The apparent viscosity of the melter feeds increases significantly with aging time for relatively high solid content melter feeds. After an aging time of 30 days, the apparent viscosity increased exponentially with solid content. A temperature increase from 25°C to 40°C reduced the apparent viscosity with the reduction becoming more evident at high solids content.
{"title":"Effects of Aging and Temperature on the Rheological Properties of Simulated Melter Feed Slurries for Nuclear Waste Vitrification","authors":"Hong Zhao, I. Muller, I. Pegg","doi":"10.1002/9781118407950.CH22","DOIUrl":"https://doi.org/10.1002/9781118407950.CH22","url":null,"abstract":"In some vitrification processes, the nuclear waste is first mixed with glass-forming additives to form an intermediate aqueous slurry before being processed through a melter at high temperature (typically 1100-1200°C) to form a glass of the desired composition and properties. The rheological characteristics of such an intermediate melter feed slurry are important for the mixing and transport of the feed slurry to the melter and also in the spreading of the slurry on the surface of the glass melt. In this paper, the effects of aging and temperature on the rheological properties of melter feed slurries have been investigated for various high-sodium waste streams. The apparent viscosity of the melter feeds increases significantly with aging time for relatively high solid content melter feeds. After an aging time of 30 days, the apparent viscosity increased exponentially with solid content. A temperature increase from 25°C to 40°C reduced the apparent viscosity with the reduction becoming more evident at high solids content.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"6 1","pages":"223-229"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84254620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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