High-temperature characterization of oxygen-deficient K2NiF4-type Nd2−xSrxNiO4−δ (x = 1.0–1.6) for potential SOFC/SOEC applications

2015 ◽  
Vol 3 (47) ◽  
pp. 23852-23863 ◽  
Author(s):  
Ekaterina Kravchenko ◽  
Dmitry Khalyavin ◽  
Kiryl Zakharchuk ◽  
Jekabs Grins ◽  
Gunnar Svensson ◽  
...  
Keyword(s):  
High Temperature ◽  
Crystal Lattice ◽  
Electronic Transport ◽  
Elevated Temperatures ◽  
Oxygen Deficiency ◽  
Electronic Conductivity

Substitution by strontium induces significant oxygen deficiency in the crystal lattice of K2NiF4-type Nd2−xSrxNiO4−δ at elevated temperatures which, in combination with significant electronic conductivity, implies enhanced mixed ionic–electronic transport.

Performance and Reliability of MEMS Gyroscopes and Packaging at High Temperatures

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000359-000366 ◽  
Author(s):  
Patrick McCluskey ◽  
Chandradip Patel ◽  
David Lemus
Keyword(s):  
High Temperature ◽  
Indoor Environment ◽  
Elevated Temperatures ◽  
High Sensitivity ◽  
Effect Of Temperature ◽  
Gps Tracking ◽  
Mems Gyroscope ◽  
Mems Gyroscopes ◽  
Gyroscope Sensor

Elevated temperatures can significantly affect the performance and reliability of MEMS gyroscope sensors. A MEMS vibrating resonant gyroscope measures angular velocity via a displacement measurement which can be on the order on nanometers. High sensitivity to small changes in displacement causes the MEMS Gyroscope sensor to be strongly affected by changes in temperature which can affect the displacement of the sensor due to thermal expansion and thermomechanical stresses. Analyzing the effect of temperature on MEMS gyroscope sensor measurements is essential in mission critical high temperature applications, such as inertial tracking of the movement of a fire fighter in a smoke filled indoor environment where GPS tracking is not possible. In this paper, we will discuss the development of the high temperature package for the tracking application, including the characterization of the temperature effects on the performance of a MEMS gyroscope. Both stationary and rotary tests were performed at room and at elevated temperatures on 10 individual single axis MEMS gyroscope sensors.

Characterization of Pyromark 2500 Paint for High-Temperature Solar Receivers

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Clifford K. Ho ◽  
A. Roderick Mahoney ◽  
Andrea Ambrosini ◽  
Marlene Bencomo ◽  
Aaron Hall ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Normal Incidence ◽  
Radiative Properties ◽  
Solar Absorptance ◽  
Thermal Emittance ◽  
Percentage Points ◽  
Original Coating

Pyromark 2500 is a silicone-based high-temperature paint that has been used on central receivers to increase solar absorptance. The radiative properties, aging, and selective absorber efficiency of Pyromark 2500 are presented in this paper for use as a baseline for comparison to high-temperature solar selective absorber coatings currently being developed. The solar absorptance ranged from ∼0.97 at near-normal incidence angles to ∼0.8 at glancing (80°) incidence angles, and the thermal emittance ranged from ∼0.8 at 100 °C to ∼0.9 at 1000 °C. After thermal aging at temperatures of ∼750 °C or higher, the solar absorptance decreased by several percentage points within a few days. It was postulated that the substrate may have contributed to a change in the crystal structure of the original coating at elevated temperatures.

Influence of Preparation Parameters on Properties of Belite Clinker

2014 ◽  
Vol 897 ◽  
pp. 3-8 ◽  
Author(s):  
Theodor Staněk
Keyword(s):  
High Temperature ◽  
Diffraction Analysis ◽  
Crystal Lattice ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydraulic Activity ◽  
Laboratory Development ◽  
Electron Microanalysis

Low-lime saturated belite clinkers were prepared under different regimes of burning in the laboratory. Development of compressive strengths of the obtained belite clinkers was evaluated in relation to the reactivity of raw meals, burning temperature and time, and degree of lime saturation. Electron and optical microscopy, X-ray diffraction analysis and high-temperature microphotometry were the methods used for characterization of belite clinkers. It was discovered that the quickly-burnt belite clinker has unexpectedly lower hydraulic activity with respect to the longer-time burnt, recrystallized clinker. The reason could be little contamination of its crystal lattice by secondary oxides as determined by electron microanalysis.

Characterization of the High-Temperature Properties of BaCe0.4Zr0.4Pr0.2O3−δ Perovskite as a Potential Material for PC-SOFC

2021 ◽  
Author(s):  
Juan Basbus ◽  
Mauricio Damian Arce ◽  
Horacio E Troiani ◽  
Fernando Prado ◽  
Liliana V. Mogni ◽  
...  
Keyword(s):  
High Temperature ◽  
Crystal Lattice ◽  
High Temperature Properties

Compounds based on barium cerates and zirconates Ba(Ce,Zr)O3−δ are oxides able to transport protons through their crystal lattice by proton hopping between oxygen sites. This feature makes them potential candidates...

Characterization of grain boundary phases in Si3N4 sintered using Y-Si-Al-O-N additives

1990 ◽  
Vol 48 (4) ◽  
pp. 1070-1071
Author(s):  
C. Koehler ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Elevated Temperatures ◽  
Secondary Phases ◽  
Amorphous Phases ◽  
High Temperature Mechanical Properties

The usefulness of silicon nitride as a high temperature ceramic can be limited by the presence of amorphous phases at the grain boundaries. Dense silicon nitride ceramics are produced using pressureless sintering of Si3N4 with Y-Si-Al-O-N additives. When these additives are left as a glassy phase at the grain boundaries and triple grain junctions, the mechanical properties at elevated temperatures are weakened due to these low viscous glasses. Post-sintering heat treatments and close compositional control can be effective in transforming the glass into crystalline phases at the grain boundaries thereby increasing the refractoriness.To optimize high temperature mechanical properties, processing must be controlled not only to fully crystallize the grain boundaries but also to avoid certain unstable secondary phases whose oxidation leads to large molar volume changes which causes possible cracking. Transmisssion electron microscopy and x-ray microanalysis (EDS) are significant methods to characterize the amorphous grain boundary pockets and to identify the crystalline grain boundary phases.

High Temperature Electrical Characterization of 4H-SiC MESFET Basic Logic Gates

2014 ◽  
Vol 778-780 ◽  
pp. 1130-1134 ◽  
Author(s):  
Mihaela Alexandru ◽  
Viorel Banu ◽  
Matthieu Florentin ◽  
Xavier Jordá ◽  
Miguel Vellvehi ◽  
...  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Schottky Contact ◽  
Electrical Characterization ◽  
Logic Gates ◽  
Basic Logic ◽  
Process Maturity ◽  
Integration Density ◽  
Device Integration

Due to our demonstrated stable Tungsten-Schottky barrier at elevated temperatures, and also thanks to our technological process maturity regarding SiC-Schottky contact fabrication, we have implemented the digital logic gates library adopting a normally-on MESFET topology. In this paper we present new experimental results showing the thermal behavior up to 300oC of 4H-SiC logic gates library, monolithically integrating normally-on MESFETs and epitaxial resistors. The implemented SiC devices are based on important CMOS features and are specially designed for large ICs device integration density.

Structure and Microstructure of Advanced Materials Characterized by Neutron Diffraction

2021 ◽  
Vol 1016 ◽  
pp. 1404-1410
Author(s):  
Pavel Strunz ◽  
Radim Kocich ◽  
Přemysl Beran ◽  
Lenka Kunčická ◽  
Debashis Mukherji ◽  
...  
Keyword(s):  
High Temperature ◽  
Neutron Diffraction ◽  
Elevated Temperatures ◽  
Advanced Materials ◽  
High Temperature Alloys ◽  
The Matrix ◽  
Structure And Microstructure ◽  
Zr Alloy

Characterization of advanced materials by neutron powder diffraction provides information not accessible by other techniques. Thanks to the low absorption of neutrons, the bulk of the material and large-grain samples can be investigated, moreover in situ at elevated temperatures. The neutron diffraction use is demonstrated on two types of technologically important materials: Ti-Zr alloy and Co-Re high temperature alloy. In Ti-Zr alloy, the residual stress relief and microstrain evolution after ECAP was established. Boron influence on TaC strengthening precipitates in Co-Re high temperature alloys was shown not to be significant at the foreseen alloy operation temperatures, although boron content has a strong influence on the matrix phase.

Evaluation of TFR-Characteristics in aWide Temperature Range

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000247-000251
Author(s):  
Uwe Partsch ◽  
Christian Lenz ◽  
Marco Wenzel ◽  
Markus Eberstein
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Elevated Temperatures ◽  
Electronic Packages ◽  
Electrical Characteristics ◽  
Sensor Applications ◽  
Thermal Range

Thick-Film Resistors (TFR) are applied for many years for the manufacturing of ceramic electronic packages as well as for mechanical or thermal sensors. The resistors characteristics (e.g. Rsqr, HTCR, CTCR) are guaranteed by paste suppliers for a thermal range of operation between −55 and 125°C. However, specific sensor applications require higher operation temperatures of up to 500°C. In the paper the results of the characterization of commercial TFR at elevated temperatures on alumina substrates are presented. Electrical characteristics (e.g. Rsqr, HTCR, CTCR, GF) are correlated with materials characteristics (TFR thermal expansion, glass transition temperature, microstructure). Different requirements are discussed regarding an improved high temperature applicability of TFR. Advantages and limits of the commercial TFR will be presented.

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