Textured Barium Hexaferrite Films on Silicon Substrates with Aluminum Oxide and Titanium Oxide Barrier Layers

2021 ◽  
Vol 66 (12) ◽  
pp. 1802-1810
Author(s):  
V. G. Kostishin ◽  
A. Yu. Mironovich ◽  
A. V. Timofeev ◽  
R. I. Shakirzyanov ◽  
I. M. Isaev ◽  
...  
2010 ◽  
Vol 2 (7) ◽  
pp. 1835-1843 ◽  
Author(s):  
Irina Gouzman ◽  
Olga Girshevitz ◽  
Eitan Grossman ◽  
Noam Eliaz ◽  
Chaim N. Sukenik

2018 ◽  
Vol 32 (16) ◽  
pp. 1850199 ◽  
Author(s):  
Degao Lan ◽  
Xiaofeng Zhao ◽  
Fei Wang ◽  
Chunpeng Ai ◽  
Dianzhong Wen ◽  
...  

The humidity sensor based on silicon substrate is presented in this paper, which consists of anodic aluminum oxide (AAO) film and interdigitated electrodes. By using electro-chemical oxidizing technique, AAO film with high porosity is fabricated on the silicon substrate. Under optimal oxidization condition, pore diameter of 37–79 nm and depth about [Formula: see text]m is achieved. Interdigitated electrodes are fabricated on the top of AAO film by vacuum evaporation deposition method. The results show that the sensor has different nonlinear response in whole range of relative humidity (RH). Moreover, it has almost linear relationship between the capacitance and RH at high RH from 75% to 95%. The highest sensitivity is obtained 613 pF/%RH at 1 kHz, which is much higher than other frequencies.


Author(s):  
Jorge Silva-Yumi ◽  
Telmo Moreno Romero ◽  
Gabriela Chango Lescano

Nanofluids constitute an alternative for the most efficient use of energy as they allow generating or improving thermal properties among others of traditional fluids, they are defined as so-called base fluids, such as: water, ethylene glycol, oils, etc., which contain nanoparticles in suspension , such as: aluminum oxide, silicon oxide, titanium oxide, metal nanoparticles, carbon nanotubes, graphene, carbides, etc. Nanofluids can be synthesized by two methods, the nanoparticles can be obtained separately and then the nanofluid is prepared or both nanoparticles and the nanofluid can be prepared simultaneously, an important factor to consider in obtaining nanofluids is their stability. Stability can be achieved by physical treatment or chemical treatment using surfactants. There are many studies about nanofluids, however, most are obtained with synthetic nanoparticles, leaving the use of natural nanoparticles as a field to be explored, as well as other surfactants to improve their stability. Keywords: nanofluids, hybrid nanofluids, nanoparticles, nano refrigerant. Resumen Los nanofluidos constituyen una alternativa para el uso más eficiente de energía pues permiten generar o mejorar las propiedades térmicas entre otras de los fluidos tradicionales, son definidos como fluidos denominados base, como: agua, etilenglicol, aceites, etc., que contienen nanopartículas en suspensión, como: óxido de aluminio, óxido de silicio, óxido de titanio, nanopartículas metálicas, nanotubos de carbono, grafeno, carburos, etc. Los nanofluidos se pueden sintetizar por dos métodos, se pueden obtener las nanopartículas por separado y luego preparar el nanofluido o se puede preparar simultáneamente las nanopartículas y el nanofluido, un factor importante a considerar en la obtención de nanofluidos es su estabilidad. La estabilidad se puede lograr mediante tratamiento físico o tratamiento químico mediante la utilización de surfactantes. Existen muchos estudios acerca de nanofluidos sin embargo, la mayoría se obtienen con nanopartículas sintéticas, quedando el uso de nanopartículas naturales como un campo por explorar al igual que otros surfactantes para mejorar su estabilidad. Palabras Clave: nanofluidos, nonofluidos híbridos, nanoparticulas, nanorefrigerantes.


2021 ◽  
Author(s):  
Shima El-Shemy ◽  
Mostafa Eissa ◽  
Aly Arafa

Abstract It is interesting to note in recent years for a large number of researchers the topic of photonic crystals (PhCs) because of their new and useful properties. In addition, there are many advantages to photonic crystals materials as a high reflectance materials as well as the high transmittance materials based on the target application. The calculations were done for Aluminum oxide and titanium oxide (Al2O3/TiO2) composite photonic crystal in one dimension, which shows a high reflectivity (~ 99 %). The chosen photonic crystal composite can be useful to reflect the Cherenkov light many times which comes out from Cherenkov radiation by using radioisotope 90Sr-90Y. The output intensified light has power 1.45 µwatt and 1.45 nwatt for 90Sr-90Y with the activity 1Ci and 1mCi respectively, that can be used for micro/nano-power source applications.


2016 ◽  
Vol 51 (7) ◽  
pp. 965-969 ◽  
Author(s):  
Daniel Choi ◽  
Boo Hyun An ◽  
Mariam Mansouri ◽  
Dima Ali ◽  
Malathe Khalil ◽  
...  

We have designed and demonstrated a complementary metal-oxide-semiconductor compatible process for fabricating high capacitance micro-capacitors based on vertically grown silver nanowires on silicon substrates. Array of silver nanowires with high-aspect ratio were electrochemically grown in the pores of anodized aluminum oxide film, which was pre-formed through anodization of aluminum thin film deposited on titanium/silicon oxide/silicon substrates. High dielectric bismuth ferric oxide layer was electrodeposited to fill the gap between silver nanowires after anodized aluminum oxide film was removed. It was found that the micro-capacitor based on the silver nanowires/bismuth ferric oxide composite film possessed higher capacitance by approximately one order of magnitude from the COMSOL simulation results from the flat Ag thin-film capacitor and the silver nanowire capacitor.


2001 ◽  
Vol 79 (19) ◽  
pp. 3158-3160 ◽  
Author(s):  
J. Carrey ◽  
K. Bouzehouane ◽  
J.-M. George ◽  
C. Ceneray ◽  
A. Fert ◽  
...  

2013 ◽  
Vol 1 (41) ◽  
pp. 12998 ◽  
Author(s):  
Tsung-Ming Yeh ◽  
Zhe Wang ◽  
Devinder Mahajan ◽  
Benjamin S. Hsiao ◽  
Benjamin Chu

1999 ◽  
Vol 122 (3) ◽  
pp. 484-493 ◽  
Author(s):  
Melissa Orme ◽  
Robert F. Smith

The use of molten aluminum droplets is investigated for potential application to precision droplet-based net-form manufacturing (PDM). In the proposed application, final structural components are made from the raw stock in one integrated operation by depositing molten metal droplets, layer after layer, via computer information. This work investigates the feasibility of the proposed technology by investigating the issues associated with generating molten aluminum droplets from capillary stream break-up, and examining the mechanical characteristics of the fabricated aluminum components. New results are presented which illustrate the generation of stable streams of molten aluminum droplets at rates of 24,000 droplets/second for a droplet stream speed of 10.9 m/s, corresponding to throughput rates of 2.3×10−4 kg/s (1.85 lb./hour). The droplets travel 2,500 droplet diameters in an inert environment before impingement with the substrate. Microstructural images are completely devoid of splat boundaries, which have been removed by remelting, and the grain size is approximately uniform throughout the field of view of the image that, in most cases presented, contains easily upwards of 30 splats. Also, it has been found that the presence of aluminum oxide in the melt does not influence the average grain size of the component. An oxide barrier however will encapsulate each grain if the oxides are not removed by filtration in the pre-jetting stage. The presence of aluminum oxide in the melt does not prohibit the removal of the splat boundaries. Mechanical analysis shows that fabrication with molten aluminum droplet deposition results in a 30 percent increase in ultimate tensile strength compared to the raw ingot stock. [S1087-1357(00)02402-3]


2007 ◽  
Vol 1034 ◽  
Author(s):  
Thottam Kalkur ◽  
Troung Troung

AbstractThe high frequency operation of BST capacitors necessitates the development of low series resistance electrodes. As an alternative to platinum, DC magnetron sputtered IrO2/Aluminum top electrode metallization for BST capacitors has been proposed. The capacitance voltage characteristics of BST capacitors did not change significantly due to the deposition of aluminum on iridium oxide. Post annealing in nitrogen environment shows that IrO2/Al metallization does not degrade annealing temperature up to 450 oC.


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