Evaluation of Composites Containing Hollow Ni/Fe-Co Fibers on Near-Field Electromagnetic Wave Absorbing Properties

2010 ◽  
Vol 123-125 ◽  
pp. 1223-1226 ◽  
Author(s):  
Jin Woo Yi ◽  
Sang Bok Lee ◽  
Jin Bong Kim ◽  
Sang Kwan Lee ◽  
Ki Hyeon Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Near Field ◽  
Hollow Structure ◽  
Substrate Material ◽  
Strip Line ◽  
Metal Powders ◽  
Polymeric Thin Films ◽  
Treatment Conditions ◽  
Electroless Metal Plating

In order to develop an effective near-field electromagnetic (EM) wave absorber, we have fabricated polymeric thin films including hollow metallic microfibers. Hydrolyzed polymer micro fibers (~2.5 ㎛) were used as a substrate material for the electroless metal plating. Nickel and subsequent Fe-Co metal layers were coated on the surface of activated polymer fibers and then heat treatment for the hollow structure as well as the densification of metallic layers was performed under the Argon atmosphere. Unlike conventional particulate or flaky metal powders, these fibers can play a significant role in elevating the magnetic property of polymer films, resulting in the increased efficiency of EM absorbing properties. In addition, their hollow structure can also lower their apparent density. SEM and EDS analysis were carried out to verify the morphology and metal compositions. Polymeric thin films containing hollow Ni/Fe-Co micro fibers were prepared to investigate the effect of metal compositions, filler distribution and heat treatment conditions on not only the near-field absorbing performance, but also magnetic properties such as permeability and magnetization. For the measurement of near-field EM absorbance in the frequency range of ~6GHz, micro strip line and network analyzer were used.

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

Influence of Laser Heat Treatment on Fracture Strength of Ceramic Thin Film

2012 ◽  
Vol 566 ◽  
pp. 145-149
Author(s):  
Hirotaka Tanabe ◽  
Keiji Ogawa ◽  
Yui Izumi ◽  
Tohru Takamatsu ◽  
Heisaburo Nakagawa ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Fracture Strength ◽  
Strength Loss ◽  
Substrate Material ◽  
Laser Quenching ◽  
Ceramic Thin Films ◽  
Film Hardness ◽  
Induced Changes ◽  
Substrate Hardness

In our previous study, it has been shown that improvement of the adhesive strength and substrate hardness of ceramic coated steels without compromising the film hardness can be achieved by applying laser quenching. In the present research, in order to demonstrate further development of this method, the fracture strength of laser-irradiated ceramic thin films (CrAlN, TiAlN and CrN) was investigated by sphere indentation testing. To prevent heat-induced changes in the substrate hardness, a cemented carbide WC-Co rather than steel was used as substrate material. While the fracture strength of each film decreased significantly through furnace heat treatment, it remained almost unchanged in case of the laser irradiated films. Laser quenching has been shown to effectively reduce the fracture strength loss of the ceramic thin films in coated steels.

Formation of Nanocrystallites in the nc-Si Films by Co-Sputtering Aluminium and Silicon

2007 ◽  
Vol 124-126 ◽  
pp. 495-498 ◽  
Author(s):  
Jae Hyun Shim ◽  
Nam Hee Cho
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Al Doping ◽  
Treatment Conditions ◽  
Main Target ◽  
Pl Intensity ◽  
Si Films ◽  
Post Deposition ◽  
Si Nanocrystallites

The nanostructural and optical features of Al-doped Si thin films, which were prepared by co-sputtering Al-chips and a Si main target, were investigated in terms of Al-doping and post-deposition heat-treatment conditions; the heat treatment was carried out at temperatures of 400 ~ 1100 °C. The structural and chemical features are related with the photoluminescence (PL) phenomena of the films. The PL intensity as well as the concentration of Si nanocrystallites were increased by doping particular amount of Al in the films.

Strong Hole Self-Doping in LaMnO3 Thin Film on a-SiO2 Substrate Produced by Metal Organic Decomposition Method

2019 ◽  
Vol 962 ◽  
pp. 17-21 ◽  
Author(s):  
Hiromi Kobori ◽  
Tohru Kitamura ◽  
Toshifumi Taniguchi ◽  
Tetsuo Shimizu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Heat Treatment ◽  
Single Crystal ◽  
Decomposition Method ◽  
Treatment Conditions ◽  
Gas Atmosphere ◽  
Metal Organic ◽  
Temperature Time ◽  
Organic Decomposition

We have studied the strong hole self-doping into LaMnO3(LMO) thin films produced by metal organic decomposition (MOD) method. With different heat treatment conditions, LMO thin films have been prepared by the MOD method in the 100 % O2gas atmosphere. We consider that the excess of O2-ions in LMO thin films induces the strong hole self-doping into LMO ones. The quantity of excess O2-ions in LMO is sensitive to the heat treatment conditions of the LMO production, especially the temperature, time and atmosphere gas. Although LMO single crystal is an antiferromagnetic insulator, LMO thin films we have produced in the 100 % O2gas atmosphere by use of the MOD method shows the properties of ferromagnetic metal.

Influence of Heat Treatment Conditions on the Properties of Vanadium Oxide Thin Films for Thermochromic Applications

2016 ◽  
Vol 16 (5) ◽  
pp. 4968-4972 ◽  
Author(s):  
Donguk Kim ◽  
Samyoung Kwon ◽  
Young Park ◽  
Jin-Hyo Boo ◽  
Sang-Hun Nam ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Vanadium Oxide ◽  
Oxide Thin Films ◽  
Treatment Conditions ◽  
Vanadium Oxide Thin Films

Preparation and Properties of Porous Bismuth Films

1998 ◽  
Vol 545 ◽  
Author(s):  
W. -N. Shen ◽  
B. Dunn ◽  
F. Ragot ◽  
M. S. Goorsky ◽  
C. D. Moore ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Phonon Transport ◽  
Treatment Temperature ◽  
Chemical Solution ◽  
Seebeck Coefficients ◽  
Treatment Conditions ◽  
Bismuth Films ◽  
Inorganic Thin Films ◽  
Controlled Porosity

AbstractThe use of chemical solution routes to form inorganic thin films is a relatively new method which represents an alternative to vapor phase routes. The present study involves the use of a chemical solution route, the decomposition of metal carboxylates, to prepare bismuth thin films of controlled porosity. Such morphologies offer the opportunity to disrupt phonon transport without greatly affecting electrical conductivity and bismuth represents a well known system in which to investigate these effects. Porous bismuth thin films have been prepared using bismuth 2-ethylhexanoate (Bi[OOCCH(C2H5)C4H9]3) as the precursor in a solvent of 2-methyl- 1-propanol. The solution is deposited on glass, Kapton, silicon, alumina or magnesia substrates by spin coating and heated to between 250 – 300°C in hydrogen. Heat treatment temperature and time are important for controlling film microstructure as both pore volume (25 to 50%) and preferred orientation depend upon heat treatment conditions. Bismuth films (62 nm thick) with 32% porosity exhibit conductivities in the range of 150 S/cm with Seebeck coefficients comparable to that of bulk materials.

The Heat Treatment Characteristics of Hydroxyapatite Thin Films Deposited by RF Sputtering

2007 ◽  
Vol 124-126 ◽  
pp. 1433-1436
Author(s):  
Chan Hoi Jung ◽  
Soon Kook Kim ◽  
Chang Woo Jang ◽  
Jun Hee Lee ◽  
Su Ho Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Vickers Hardness ◽  
Bonding Strength ◽  
Rf Sputtering ◽  
Optical Microscope ◽  
Experimental Results ◽  
Treatment Characteristics ◽  
Treatment Conditions ◽  
Heat Treated

RF sputtering process was applied to produce thin hydroxyapatite(HAp, Ca10(PO4)6(OH)2) films on Ti-6Al-4V alloy substrates. The effects of different heat treatment conditions on the bonding strength between HAp thin films and Ti-6Al-4V alloy substrates were studied. Before deposition, the Ti-6Al-4V alloy substrates were heat treated for 1hr at 850°C under 3.0×10-3torr, and after deposition, the HAp thin films were heat treated for 1hr at 400°C, 600°C and 800°C under the atmosphere, and analyzed optical microscope, FESEM, FTIR, XRD, nano-indentor, micro-vickers hardness, respectively. Experimental results represented that the HAp thin films on the heat treated substrates had higher hardness than none-heat treated substrates before the deposition.

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