scholarly journals Subsolidus phase equilibria in the PbO-poor part of the TiO2–PbO–SiO2 system and its application in low-temperature thick-film dielectrics

2006 ◽  
Vol 21 (12) ◽  
pp. 3210-3214 ◽  
Author(s):  
Marko Hrovat ◽  
Thomas Maeder ◽  
Caroline Jacq ◽  
Janez Holc ◽  
Janez Bernard
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Phase Equilibria ◽  
Thick Film ◽  
Crystalline Phase ◽  
Softening Point ◽  
Subsolidus Phase ◽  
Temperature Firing ◽  
Tie Lines ◽  
Kinetics Of

Subsolidus equilibria in the PbO-poor part of the TiO2–PbO–SiO2 diagram were studied with the aim of investigating possible applications for low-temperature thick-film dielectrics. The tie lines are between PbTiO2 and PbSiO3, and between PbTiO3 and SiO2. The results show that the TiO2, when added to low-temperature softening point glasses, reacts with the PbO from the glass, so forming PbTiO3. These results were applied to a low-temperature firing dielectric, consisting of a lead-rich PbO–SiO2–B2O3 glass filled with a TiO2 powder. The conversion of TiO2 to the PbTiO3 crystalline phase was observed above firing temperatures of approximately 600 °C. The kinetics of the reaction depend on the particle size of the TiO2.

Subsolidus phase equilibria in the La2O3–Ga2O3–NiO system

1999 ◽  
Vol 14 (6) ◽  
pp. 2351-2354 ◽  
Author(s):  
Marko Hrovat ◽  
Slavko Bernik ◽  
Janez Holc ◽  
Zoran Samardžija
Keyword(s):  
Fuel Cells ◽  
Phase Equilibria ◽  
Solid Oxide Fuel Cells ◽  
Solid Electrolyte ◽  
Ternary Compound ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Subsolidus Phase ◽  
Tie Lines

Subsolidus equilibria in air in the La2O3–Ga2O3–NiO system were studied with the aim of obtaining information on possible interactions between a LaGaO3-based solid electrolyte and NiO during preparation of the anode in solid oxide fuel cells (SOFC). No ternary compound was found. The tie lines are between La4Ga2O7 and La2NiO4, LaGaO3 and La2NiO4, LaGaO3 and NiO, and LaGaO3 and NiGa2O4.

Subsolidus phase equilibria in the La2O3–Ga2O3–CeO2 system

1999 ◽  
Vol 14 (12) ◽  
pp. 4460-4462 ◽  
Author(s):  
Marko Hrovat ◽  
Zoran Samardžzija ◽  
Janez Holc ◽  
Slavko Bernik
Keyword(s):  
Solid Solution ◽  
Phase Equilibria ◽  
Solid Oxide Fuel Cells ◽  
Solid Electrolyte ◽  
Solid Solutions ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Subsolidus Phase ◽  
Solid Solution Range ◽  
Tie Lines

Subsolidus equilibria in air in the La2O3–Ga2O3–CeO2 system were studied with the aim of obtaining information on possible interactions between a LaGaO3-based solid electrolyte and CeO2 during preparation of the anode in solid oxide fuel cells. No ternary compound was found. The tie lines are between La4Ga2O9 and the end of the CeO2 solid solution range with composition La0.5Ce0.5O1.75 and between the LaGaO3 and CeO2 range of solid solutions.

A low-temperature firing thick film capacttor material based on lead iron niobate/tungstate

1984 ◽  
Vol 19 (12) ◽  
pp. 1543-1549 ◽  
Author(s):  
T.C. Reiley ◽  
J.V. Badding ◽  
D.A. Payne ◽  
D.A. Chance
Keyword(s):  
Low Temperature ◽  
Thick Film ◽  
Temperature Firing ◽  
Iron Niobate

scholarly journals Modification of Thick-Film Conductors Used in IP Technology for Reduction of Warpage during Co-Firing of LTCC (Low Temperature Co-Fired Ceramic) Modules

2007 ◽  
Vol 336-338 ◽  
pp. 746-749 ◽  
Author(s):  
Hansu Birol ◽  
Thomas Maeder ◽  
Peter Ryser
Keyword(s):  
Low Temperature ◽  
Thick Film ◽  
Thick Films ◽  
Shrinkage Rate ◽  
Major Difficulty ◽  
Flat Surfaces ◽  
Temperature Firing ◽  
Differential Shrinkage ◽  
Printed Materials ◽  
Screen Printed

LTCC technology offers low temperature firing (<900 °C) of a materials system, which is based on LTCC sheets/tapes and (ideally) compatible thick-film components. Screen-printed materials on LTCC tapes, such as conductor, resistor, inductor thick-films are co-fired (simultaneously fired), providing a highly-functional package. This comes along with additional benefits such as ease of LTCC tape structuring, fabrication of hermetic and complex 3-D structures, etc. The major difficulty encountered arises from the differential shrinkage rate of LTCC tape and thick-film components, which has to be avoided for fabrication of warpage-free, flat surfaces that is vital for membranes, beams, etc. Therefore the goal of this study is the reduction of deformation, by matching the shrinkage rate of conductor with that of LTCC, which is achieved by mixing the commercially-available paste with selected additives.

Kinetics of low-temperature aluminothermic reduction of iron tantalate

2021 ◽  
Vol 6 ◽  
pp. 60-72
Author(s):  
R. I. Gulyaeva ◽  
◽  
A. M. Klyushnikov ◽  
S. A. Petrova ◽  
L. Yu. Udoeva ◽  
...  
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Raw Materials ◽  
Aluminum Particle ◽  
Preexponential Factor ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Isothermal Exposure ◽  
Reduction Of Iron ◽  
Kinetics Of

The kinetics of low-temperature (900 – 1180 °C) reduction of iron tantalate (98.2 wt % FeTa2O6, 1.8 wt % Ta2O5, particle size < 0.1 mm) by excess aluminum (particle size < 0.14 mm) at the molar ratio Al:FeTa2O6 = 6 was studied. According to differential scanning calorimetry and X-ray powder diffraction, reduction is almost completed at 1180 °C, the metal products are TaFeAl, TaAl3, and Ta17Al12. Based on the results of thermokinetic calculations (Ozawa – Flynn – Wall and nonlinear regression methods), the formal mechanism of the process is represented by the Bna → CnC model, which includes two consecutive steps controlled by autocatalytically activated reactions. Kinetic parameters of the steps are: 1) Е1 = 429 kJ·mol–1, A1 = 1015.3 s–1; 2) Е2 = 176 kJ·mol–1, A2 = 103.9 s–1 (Ej is the activation energy, Aj is the preexponential factor). Prediction in the Bna → CnC model frames indicates the possibility of obtaining a reaction mixture containing ≥ 98 mol. % the final formal reduction product, with isothermal exposure in the temperature range of 1040 – 1120 °C during 1.5 – 5 minutes. The proposed model can be used to develop scientific foundations and substantiate technological modes for obtaining tantalum alloys from mineral and technogenic raw materials.

The low temperature aluminising kinetics of hot-work tool steels

2012 ◽  
Vol 67 (2) ◽  
pp. 133-139
Author(s):  
B. Matijević ◽  
I. Kumić ◽  
T. Belić
Keyword(s):  
Low Temperature ◽  
Tool Steels ◽  
Kinetics Of ◽  
Hot Work Tool Steels

Kinetics of catalytic conversion of methanol at higher pressures

1980 ◽  
Vol 45 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour
Keyword(s):  
Low Temperature ◽  
Reaction Kinetics ◽  
Water Vapour ◽  
Kinetic Data ◽  
Catalytic Conversion ◽  
The Given ◽  
Kinetics Of

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.

Phase transformation and Raman spectra in BaTiO3 nanocrystals

2002 ◽  
Vol 718 ◽  
Author(s):  
Jian Yu ◽  
X. J. Meng ◽  
J.L. Sun ◽  
G.S. Wang ◽  
J.H. Chu
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Low Temperature ◽  
Long Range ◽  
Lattice Expansion ◽  
Inversion Symmetry ◽  
Range Interaction ◽  
Cooperative Phenomena ◽  
Long Range Interaction ◽  
Hydrothermal Methods

AbstractIn this paper, size-induced ferroelectricit yweakening, phase transformation, and anomalous lattice expansion are observed in nanocrystalline BaTiO3 (nc-BaTiO3) deriv ed b y low temperature hydrothermal methods, and they are w ellunderstood using the terms of the long-range interaction and its cooperative phenomena altered by particle size in covalen t ionic nanocrystals. In cubic nc-BaTiO3, five modes centerd at 186, 254, 308, 512 and 716 cm-1 are observed Raman active in cubic nanophase, and they are attributed to local rhombohedral distortion breaking inversion-symmetry in cubic nanophase. The254 and 308 cm-1 modes are significantly affected not only by the concentration of hydroxyl defects, but also their particular configuration. And the 806 cm-1 modes found to be closely associated with OH - absorbed on grain boundaries.

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