Single-domain Yba2Cu3Oy thick films and fabrics prepared by an infiltration and growth process

2001 ◽  
Vol 16 (4) ◽  
pp. 955-966 ◽  
Author(s):  
E. Sudhakar Reddy ◽  
J. G. Noudem ◽  
M. Tarka ◽  
G. J. Schmitz
Keyword(s):  
Liquid Phase ◽  
Thick Film ◽  
Growth Process ◽  
Thick Films ◽  
Solidification Process ◽  
Film Coating ◽  
Single Domain ◽  
Free Standing ◽  
Liquid Phases ◽  
Woven Structure

An infiltration and growth process has been developed to produce single-domain Yba2Cu3Oy(123) as thick films on various substrates or as self-supporting fabrics. Commercially available Y2O3 cloths of square woven or satin woven structure were infiltrated with liquid phases from a suitable source containing barium cuprates and copper oxides and subsequently converted into Y2BaCuO5(211) and −123 phases by a series of distinct peritectic reactions. Depending on the final form of 123, the Y2O3 cloth was either clamped firmly at corners to produce a self-supporting 123 fabric or placed on a suitable substrate to result in a thick film coating of 123. The source material for the liquid phase being in the form of solid blocks was placed at corners of the cloth in the case of free-standing 123 fabrics. In case of the thick film configuration the liquid phase powder was spread on the surface of the Y2O3 cloth. A small c-axis-oriented MgO or Nd(123) seed was used to generate an oriented 123 domain in the infiltrated fabric. The solidification process was optimized to transform the entire Y2O3 fabric into a single-domain 123. The microstructure of the single domain was optimized in terms of 211 size and content for high Jc. A detailed description of the process, the growth mechanism, the resulting microstructures was given, and basic superconducting properties of the new form of 123 are briefly discussed.

Fixed Grid Simulation of Radiation-Conduction Dominated Solidification Process

2009 ◽  
Vol 132 (2) ◽  
Author(s):  
Piotr Łapka ◽  
Piotr Furmański
Keyword(s):  
Liquid Phase ◽  
Thermal Radiation ◽  
Solid Phase ◽  
Solidification Process ◽  
Numerical Approach ◽  
Immersed Boundary ◽  
Fixed Grid ◽  
Semitransparent Materials ◽  
Liquid Phases ◽  
Solidification Processes

In this paper conduction-radiation controlled solidification process of semitransparent materials was numerically analyzed. New approach in this kind of simulations, which is based on the fixed grid front tracking method combined with the immersed boundary technique, was adopted and examined. The presented method enables accurate dealing with solidification processes of semitransparent materials which have different optical and thermophysical properties of solid and liquid phases as well as with absorption, emission, and reflection of the thermal radiation at the solid-liquid interface without applying moving mesh methods. The proposed numerical approach was examined by solving several simplified thermal radiation problems with complex fixed and moving boundaries both in two-dimensional and axisymmetric spaces. For some of them the accuracy of obtained results was proved by comparing with reference works, other showed capabilities of the proposed method. For simplified solidification processes of semitransparent materials three configurations of optical properties, i.e., semitransparent solid phase and opaque liquid phase, opaque solid phase and semitransparent liquid phase, and semitransparent both phases were considered. The interface between solid and liquid phases was treated to be opaque, absorbing, emitting, and reflecting diffusely the thermal radiation. Results of the numerical simulations show that the presented numerical approach works well in this kind of problems and is promising for simulation of real solidification processes of semitransparent materials.

scholarly journals Piezoelectric Thick Film Deposition via Powder/Granule Spray in Vacuum: A Review

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 59
Author(s):  
Deepak Rajaram Patil ◽  
Venkateswarlu Annapureddy ◽  
J. Kaarthik ◽  
Atul Thakre ◽  
Jun Akedo ◽  
...  
Keyword(s):  
Thick Film ◽  
Thick Films ◽  
Cost Effective ◽  
Aerosol Deposition ◽  
Ceramic Coatings ◽  
Film Deposition ◽  
Energy Harvesters ◽  
Ceramic Films ◽  
Dense Ceramic ◽  
Processing Techniques

Conventional thin-film processing techniques remain inadequate for obtaining superior dense ceramic thick films. The incompatibility of ceramic films prepared via other methods, such as screen printing, spin coating, and sputtering, is a major obstacle in the fabrication of thick film-based ceramic electronic components. The granule spray in vacuum (GSV) processes and aerosol deposition (AD) are important coating approaches for forming dense ceramic thick films featuring nanoscale crystallite structures at room temperature, which offer excellent material properties and facilitate cost-effective production. AD ceramic coatings require the acceleration of solid-state submicron ceramic particles via gas streams with a velocity of a few hundred meters per second, which are then wedged onto a substrate. This process is economical and particularly useful for the fabrication of piezoelectric thick film-based microactuators, energy harvesters, sensors, and optoelectronic devices. More recently, the GSV technique was improved to achieve more uniform and homogeneous film deposition after AD. This review article presents a detailed overview of the AD and GSV processes for piezoelectric thick films in terms of recent scientific and technological applications.

scholarly journals Examination of Thick-Films Using Modern Surface Analytical Techniques

1984 ◽  
Vol 11 (3) ◽  
pp. 219-223 ◽  
Author(s):  
G. Harsányi ◽  
G. Ripka
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Analytical Methods ◽  
Thick Films ◽  
Analytical Techniques ◽  
Electrical Measurements ◽  
Surface Impurity ◽  
And Migration

Modern surface analytical methods/EMPA, AES, SIMS etc. were used for studying the different layers in thick-film integrated circuits. Diffusion and migration effects, surface impurity distributions and surface compositions were examined. Some of the results are presented in this paper. Electrical measurements are not discussed here; only examples of the practical use of the methods are demonstrated.

A neutralization charge detection method for detecting ions under ambient and liquid-phase conditions

2016 ◽  
Vol 52 (29) ◽  
pp. 5187-5189 ◽  
Author(s):  
Ko-Keng Chang ◽  
Yi-Hong Cai ◽  
Chung-Hsuan Chen ◽  
Yi-Sheng Wang
Keyword(s):  
Liquid Phase ◽  
Detection Method ◽  
Sensitive Detection ◽  
Charge Detection ◽  
Liquid Phases

A novel neutralization charge detection method enabling the fast and sensitive detection of ions under ambient and liquid phases.

scholarly journals The Intramolecular Pressure and the Extension of the Critical Point’s Influence Zone on the Order Parameter

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jose Luis Rivera ◽  
Homero Nicanor-Guzman ◽  
Roberto Guerra-Gonzalez
Keyword(s):  
Transition Temperature ◽  
Critical Temperature ◽  
Liquid Phase ◽  
Order Parameter ◽  
Bulk Liquid ◽  
Influence Zone ◽  
Molecular Potential ◽  
Liquid Phases ◽  
Dynamics Simulations ◽  
Wide Zone

The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone covers up to hundreds of degrees below the critical temperature. Here we show that, for ethane, the experimental critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes, and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase, using a simple molecular potential. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, Molecular Dynamics simulations reveal that the experimentally observed wide extension of the critical influence zone is the result of a vapor-like effect due to low bulk liquid phase densities.

Stress Evaluation on Hetero-Epitaxial 3C-SiC Film on (100) Si Substrates

2012 ◽  
Vol 717-720 ◽  
pp. 521-524 ◽  
Author(s):  
Ruggero Anzalone ◽  
M. Camarda ◽  
C. Locke ◽  
J. Carballo ◽  
N. Piluso ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Process ◽  
Film Growth ◽  
Raman Shift ◽  
Fundamental Parameter ◽  
Free Standing ◽  
Si Substrates ◽  
Shift Analysis ◽  
Hydrogen Carrier ◽  
The Impact

SiC is a candidate material for micro- and nano-electromechanical systems (MEMS and NEMS). In order to understand the impact that the growth rate has on the residual stress of CVD-grown 3C-SiC hetero-epitaxial films on Si substrates, growth experiments were performed and the resulting stress was evaluated. Film growth was performed using a two-step growth process with propane and silane as the C and Si precursors in hydrogen carrier gas. The film thickness was held constant at ~2.5 µm independent of the growth rate so as to allow for direct films comparison as a function of the growth rate. Supported by profilometry, Raman and micro-machined free-standing structures, this study shows that the growth rate is a fundamental parameter for low-defect and low-stress hetero-epitaxial growth process of 3C-SiC on Si substrates. Stress analysis performed by modify Stoney’s equation trough optical curvature measurement, Raman shift analysis and micro-machining of free-standing structures that shows apparent disagreement about the nature of the stress. These odds between the experimental data can be explained assuming a strong stress field located in the substrate and related to defects generated in the silicon during the growth process.

GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART III. THE USE OF OLEIC ACID ESTERS AS LIQUID PHASES

1961 ◽  
Vol 39 (6) ◽  
pp. 1190-1199 ◽  
Author(s):  
E. von Rudloff
Keyword(s):  
Liquid Phase ◽  
Rapeseed Oil ◽  
Hydroxyl Groups ◽  
Gas Liquid Chromatography ◽  
Retention Data ◽  
Geometrical Isomers ◽  
Potassium Oleate ◽  
Liquid Phases ◽  
Degree Of Separation ◽  
Poly Ethylene

The separation of several cyclic terpene hydrocarbons and some oxygenated derivatives was studied on a variety of triglyceride and dioleate ester columns. Use of rapeseed oil, partially hydrogenated rapeseed oil, olive oil, triolein, tristearin, methyl oleate, and potassium oleate as liquid phases led to the conclusion that the presence of an esterified mono-unsaturated long-chain acid is a desirable constituent of the liquid phase. Dioleate esters of 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polyethylene glycol showed useful differences in the degree of separation of both terpene hydrocarbons and oxygenated derivatives. Ether linkages, as in the di- and poly-ethylene glycol ester, also were associated with favorable separations. When the liquid phase contained free hydroxyl groups, the degree of separation of hydrocarbons and ketones was in general less favorable. The spacing of the ester groups was found to have some effect on retention data. The separation of such critical pairs of isomers as tricyclene and α-pinene, α-fenchene and camphene, and also geometrical isomers of oxygenated derivatives is facilitated by use of several of these liquid phases.

Collision induced microwave absorption in N2, CH4, and CF4 in the gaseous and liquid phases

1977 ◽  
Vol 55 (6) ◽  
pp. 496-505 ◽  
Author(s):  
J. L. Urbaniak ◽  
I. R. Dagg ◽  
G. E. Reesor
Keyword(s):  
Liquid Phase ◽  
Microwave Absorption ◽  
Low Density ◽  
Temperature Range ◽  
Liquid Phases ◽  
Gas To Liquid

Measurements of collision induced microwave absorption at 2.3 cm−1 have been carried out on gaseous N2 in the temperature range from 124 to 156 K and on liquid N2 in the temperature range from 77 to 125 K. The low density gaseous measurements have been found to agree well with the previous microwave and infrared results and with existing theories. The dependence of the absorption on density has been obtained at 156 K up to a density of 400 amagat and the results compared with the absorption in the liquid at the same density. The absorption is found to be a function of temperature and density but does not depend on the molecules being in a gas or liquid phase. Results for liquid CH4 and CF4 are reported and compared with previous microwave gaseous results. In contrast to the results for N2 the dependence on the square of the density changes by a relatively small amount in going from the low density gas to liquid densities.

Multiphase Reactions and Reactors

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Liquid Phase ◽  
Solid Phase ◽  
Complete Classification ◽  
Catalytic Reactions ◽  
Two Phase ◽  
Multiphase Reactions ◽  
Liquid Phases ◽  
Three Phase ◽  
Solid Form

The first three chapters of this part dealt with two-phase reactions. Although catalysts are not generally present in these systems, they can be used in dissolved form in the liquid phase. This, however, does not increase the number of phases. On the other hand, there are innumerable instances of gas-liquid reactions in which the catalyst is present in solid form. A popular example of this is the slurry reactor so extensively employed in reactions such as hydrogenation and oxidation. There are also situations where the solid is a reactant or where a phasetransfer catalyst is immobilized on a solid support that gives rise to a third phase. A broad classification of three-phase reactions and reactors is presented in Table 17.1 (not all of which are considered here). This is not a complete classification, but it includes most of the important (and potentially important) types of reactions and reactors. The thrust of this chapter is on reactions and reactors involving a gas phase, a liquid phase, and a solid phase which can be either a catalyst (but not a phasetransfer catalyst) or a reactant, with greater emphasis on the former. The book by Ramachandran and Chaudhari (1983) on three-phase catalytic reactions is particularly valuable. Other books and reviews include those of Shah (1979), Chaudhari and Ramachandran (1980), Villermaux (1981), Shah et al. (1982), Hofmann (1983), Crine and L’Homme (1983), Doraiswamy and Sharma (1984), Tarmy et al. (1984), Shah and Deckwer (1985), Chaudhari and Shah (1986), Kohler (1986), Chaudhari et al. (1986), Hanika and Stanek (1986), Joshi et al. (1988), Concordia (1990), Mills et al. (1992), Beenackers and Van Swaaij (1993), and Mills and Chaudhari (1997). Doraiswamy and Sharma (1984) also present a discussion of gas-liquid-solid noncatalytic reactions in which the solid is a reactant. In Chapter 7 we saw how Langmuir-Hinshelwood-Hougen-Watson (LHHW) models are normally used to describe the kinetics of gas-solid (catalytic) or liquid-solid (catalytic) reactions, and in Chapters 14 to 16 we saw how mass transfer between gas and liquid phases can significantly alter the rates and regimes of these two-phase reactions.

scholarly journals The Role of Sacrificial and/or Protective Layers to Improve the Sintering of Electroactive Ceramics: Application to Piezoelectric PZT-Printed Thick Films for MEMS

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 453-475
Author(s):  
Hélène Debéda ◽  
Maria-Isabel Rua-Taborda ◽  
Onuma Santawitee ◽  
Simon Grall ◽  
Mario Maglione ◽  
...  
Keyword(s):  
Thick Film ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Thick Films ◽  
Protective Layer ◽  
Protective Layers ◽  
Plasma Sintering ◽  
Wide Range ◽  
Spark Plasma ◽  
Pros And Cons

Piezoelectric thick films are of real interest for devices such as ceramic Micro-ElectroMechanical Systems (MEMS) because they bridge the gap between thin films and bulk ceramics. The basic design of MEMS includes electrodes, a functional material, and a substrate, and efforts are currently focused on simplified processes. In this respect, screen-printing combined with a sacrificial layer approach is attractive due to its low cost and the wide range of targeted materials. Both the role and the nature of the sacrificial layer, usually a carbon or mineral type, depend on the process and the final device. First, a sacrificial layer method dedicated to screen-printed thick-film ceramic and LTCC MEMS is presented. Second, the recent processing of piezoelectric thick-film ceramic MEMS using spark plasma sintering combined with a protective layer approach is introduced. Whatever the approach, the focus is on the interdependent effects of the microstructure, chemistry, and strain/stress, which need to be controlled to ensure reliable and performant properties of the multilayer electroceramics. Here the goal is to highlight the benefits and the large perspectives of using sacrificial/protective layers, with an emphasis on the pros and cons of such a strategy when targeting a complex piezoelectric MEMS design.

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