Characterization of silicate sensors on Low Temperature Cofire Ceramic (LTCC) substrates using DSC and XRD techniques

2012 ◽  
Vol 2012 (1) ◽  
pp. 000598-000603
Author(s):  
Mary Ruales ◽  
Kinzy Jones
Keyword(s):  
Low Temperature ◽  
Phase Diagrams ◽  
Cost Effective ◽  
Microelectronics Packaging ◽  
Design Structure ◽  
Recovery Times ◽  
Response And Recovery ◽  
Xrd Techniques ◽  
The Impact

Characterization of Silicate sensors using Differential Scanning Calorimeter (DSC), X-ray Diffraction (XRD) and Scanning Electron microscopy (SEM) is presented. These silicate sensors are based on three primary materials: Li2SiO3, K2SiO3, and CaSiO3. Silicate powders were transform into adequate inks that were added to a Low Temperature Cofire Ceramic (LTCC) substrates with thick film technology using screen printing which continues to offer innovative and cost effective solutions to the increasing demands for higher circuit densities. These silicate sensors are low power-high temperature heated ceramic sensors to detect halogen gases. Every sensor responded to the gas showing stability and reproducibility. Phase diagrams for these silicates were used to produce different combinations. The use of the eutectoid point in the phase diagrams was critical to reduce the operating temperature. Testing and characterization of these silicate sensors is presented. The impact of various parameters (e.g. materials design, structure, properties, performance and processing) for the sensors including their relationships for electronic packaging was reviewed and it was found critical to determine the microelectronics packaging reliability and integrity. The fundamentals of the sensor behavior including the sensitivity as well as response and recovery times were also determined.

High-T NOx Sensing Elements Using Conductive Oxides and Pt

2004 ◽  
Author(s):  
David L. West ◽  
Fred C. Montgomery ◽  
Timothy R. Armstrong
Keyword(s):  
Yttria Stabilized Zirconia ◽  
Step Response ◽  
Stabilized Zirconia ◽  
Temperature Range ◽  
Pt Electrodes ◽  
Recovery Times ◽  
Response And Recovery ◽  
Primary Variable

Development of NOx sensing elements intended for operation at T ∼600 °C are described. The elements were fabricated by depositing co-planar La1-x Srx BO3 (B = Cr, Fe) and Pt electrodes on yttria-stabilized zirconia substrates. Characterization of the elements included response to NO2 and NO as well as the [O2] dependence of the NO2 response. Much stronger (∼ 40 mV for 450 ppm NO2 in 7 vol% O2 at 600 °C) sensing responses were observed for NO2 than NO, indicating these elements are best suited for detection of NO2. Pronounced asymmetries were observed between the NO2 step response and recovery times for the elements, with temperature being the primary variable governing the recovery times in the temperature range 500–700 °C.

Low Temperature, Digital Control, Fast Synthesis of 2-D BNNSs and Their Application for Deep UV Detectors

2015 ◽  
Vol 1726 ◽  
Author(s):  
Ali Aldalbahi ◽  
Renyauan Yang ◽  
Eric Yiming Li ◽  
Muhammad Sajjad ◽  
Yihau Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Digital Control ◽  
Electronic Device ◽  
Uv Detectors ◽  
Raman Scattering Spectroscopy ◽  
Transmission Electron ◽  
Recovery Times ◽  
Response And Recovery ◽  
Deep Uv ◽  
Fast Synthesis

ABSTRACTThis paper reports low temperature, digital control, fast synthesis of high-quality boron nitride nanosheets (BNNSs) and their electronic device application. Raman scattering spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM) are used to characterize the BNNSs. With the synthesized various BNNSs, two prototypic types of deep UV photodetectors have been fabricated, and sensitivity, response and recovery times, as well as repeatability have been characterized. Effects of period and thickness of BNNSs on the properties of prototypic photodetectors are also discussed.

scholarly journals Cost effective preparation and characterization of nanocrystalline nickel ferrites (NiFe2O4) in low temperature regime

2015 ◽  
Vol 27 (2) ◽  
pp. 176-181 ◽  
Author(s):  
T. Shanmugavel ◽  
S. Gokul Raj ◽  
G. Ramesh Kumar ◽  
G. Rajarajan ◽  
D. Saravanan
Keyword(s):  
Low Temperature ◽  
Temperature Regime ◽  
Cost Effective ◽  
Nanocrystalline Nickel

Silver-Rutile UV Sensor Fabricated on Thermally Oxidized Titanium Foil

2011 ◽  
Vol 495 ◽  
pp. 18-22
Author(s):  
Mehdi Mohamadzade Lajvardi ◽  
Faramarz Hossein-Babaei ◽  
Farhad Akbari Boroumand
Keyword(s):  
Thermal Evaporation ◽  
Reverse Current ◽  
Cost Effective ◽  
Annealing Process ◽  
Titanium Foil ◽  
Uv Illumination ◽  
Recovery Times ◽  
Response And Recovery ◽  
Titanium Structure ◽  
Visible Blind

A UV-sensitive Schottky diode of Ag-rutile-Ti structure is fabricated on a thermally oxidized titanium chip. The junction is formed by the thermal evaporation of silver in vacuum and a subsequent controlled annealing process. Applying a biasing voltage of-300 mV, the reverse current of the fabricated silver-rutile-titanium structure increases five orders of magnitude under 50 µW/mm2 UV illumination ( λ=355 nm). The device is visible-blind and its operation is described based on the photoelectric mechanism in the carrier-depleted oxide layer. The dominance of the photoelectric, rather than photoconductive, mechanism along with the dense rutile layer are responsible for the fast transient times observed. The response and recovery times of the device are 800 µs and 7 ms, respectively.The device is stable and extremely cost effective.

Novel Preparation and Characterization of Fe2O3/CNT Thin Films for Flammable Gas Sensors

2019 ◽  
Vol 947 ◽  
pp. 47-51
Author(s):  
Buaworn Chaitongrat ◽  
Sutichai Chaisitsak
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Dry Process ◽  
Vapor Deposition Technique ◽  
Flammable Gas ◽  
Recovery Times ◽  
Response And Recovery

In this work, novel preparation for Fe2O3/CNT thin films was investigated. The Fe/CNT thin films were synthesized through vertical floating-catalyst chemical vapor deposition technique (FC-CVD) and subsequently annealed in air. The various annealing temperature to create Fe2O3 was examined and characterized by field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Ultraviolet–visible spectroscopy (UV-Vis) and Raman spectroscopy. In addition, effect of wet/dry process on gas sensing of Fe2O3/CNTs was also investigated. The results suggest that the interfacial oxide layer helps to significantly improve LPG sensing performance with rapid response and recovery times. The proposed method can be considered as a promising approach for producing ultra-Fe2O3/CNT thin films that are appropriate for sensing application.

scholarly journals Characterization of Flexible Multi-Walled Carbon Nanotubes Network Sensor to Freon Gas Detection

2021 ◽  
pp. 2543-2554
Author(s):  
Nisreen M. Al-Makram ◽  
Wasan R. Saleh
Keyword(s):  
Room Temperature ◽  
Filter Cake ◽  
Operating Temperature ◽  
X Ray ◽  
Before And After ◽  
Recovery Times ◽  
Multi Walled Carbon Nanotubes ◽  
Response And Recovery ◽  
Walled Carbon Nanotubes

     MWCNTs-OH was used to prepare a flexible gas sensor by deposition as a network on a filter cake using the method of filtration from suspension (FFS). The morphological and structural properties of the MWCNTs network were characterized before and after exposure to Freon gas using FTIR spectra and X-ray diffractometer, which confirmed that the characteristics of the sensor did not change after exposure to the gas. The sensor was exposed to a pure Freon134a gas as well as to a mixture of Freon gas and air with different ratios at room temperature. The experiments showed that the sensor works at room temperature and the sensitivity values increased with increasing operating temperature, to be 58% until 150 ºC. The fabricated flexible sensor has good response and recovery times at low gas concentrations of 1.3, 2, and 2.7 ppm.

Characterization of Pd Nano-Thin Films for High-Speed Switchable Mirrors

2011 ◽  
Vol 700 ◽  
pp. 166-169
Author(s):  
Chung Kiak Poh ◽  
Chung How Poh ◽  
Zai Ping Guo ◽  
Hua Kun Liu
Keyword(s):  
Thin Films ◽  
High Speed ◽  
Optical Switching ◽  
Thermal Evaporation ◽  
Film Morphology ◽  
Optical Cell ◽  
Atomic Force ◽  
Recovery Times ◽  
Response And Recovery

We fabricated Pd thin films from 2 to 35 nm thick via thermal evaporation, and a hermetically sealed hydrogen optical cell was used to characterize the films for properties such as hydrogen fractional ratio, optical switching contrast (Weber contrast), and response and recovery times. An atomic force microscope with a high resolution scanning tip was used to study the evolution of the film morphology.

scholarly journals A Novel Instrument for Real-Time Measurement of Attenuation of Weather Radar Radome Including Its Outer Surface. Part I: The Concept

2018 ◽  
Vol 35 (5) ◽  
pp. 953-973 ◽  
Author(s):  
Alessio Mancini ◽  
Jorge L. Salazar ◽  
Rodrigo M. Lebrón ◽  
Boon Leng Cheong
Keyword(s):  
Rain Rate ◽  
Cost Effective ◽  
Time Measurement ◽  
Ice Formation ◽  
Effective Solution ◽  
Real Time Measurement ◽  
Radar Systems ◽  
Calibration Methods ◽  
The Impact

AbstractThis paper presents a unique instrument for characterizing the impact of wet radomes in radar systems. The proposed technique enables full radio frequency (RF) characterization of the radome, by evaluating its performance under a variety of conditions, including dirtiness, wetness, ice formation, and varying temperature, and providing a potential solution for future wet radome calibration methods. The reflections generated from the wet radome surface, measured from a high-resolution probe, are combined with an estimation of water absorption as a function of the precipitation rain rate, to calculate the attenuation introduced by the wet radome. This instrument is a cost-effective solution that can be integrated into an existing or new radar system.

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