Electrodeposition of NiFe Thin Films and NiFe/Cu Multilayers with a Recirculating Electrochemcial Flow Reactor

1999 ◽  
Vol 562 ◽  
Author(s):  
N. V. Myungl ◽  
K. H. Ryu ◽  
J. H. Kim ◽  
M. Schwartz ◽  
K. Nobel
Keyword(s):  
Thin Film ◽  
Corrosion Resistance ◽  
Flow Reactor ◽  
Individual Layer ◽  
Nonmagnetic Metal ◽  
Α Phase ◽  
Fe Content ◽  
Magnetic Layers ◽  
Order Of Magnitude ◽  
Bulk Alloys

ABSTRACTNano-structured Ni80Fe20NCu multilayers were electrodeposited by a newly developed electrodeposition process utilizing a recirculating electrochemical flow reactor. This process, which operates in an inert gas environment, overcomes the limitations of conventional multilayer electrodeposition methods (single and dual bath techniques) by depositing pure magnetic layers without codeposition of the nonmagnetic metal and oxidation of metal interfaces. Structure, corrosion resistance and magnetic properties of electrodeposited NiFe (0 to 100 % Fe) thin film alloys were first investigated. Three different crystal regions, α, mixed α and γ, and γ phases were observed at <50,;50, >50 % Fe in the deposit, respectively. The narrow mixed phase regions was around 50 % Fe compared to 70–80% Fe for bulk alloys. The lattice parameters of electrodeposited alloys exhibited the same trends as bulk alloys. Maximum corrosion resistance was obtained at 50% Fe content in 0.5 M NaCl similar to bulk alloys. The corrosion resistance of the α phase was an order of magnitude less than the γ phase. The magnetoresistance (MR) of electrodeposited NiFe thin film alloys was higher than bulk alloys. Based on these studies, Ni80Fe20/Cu multilayers with individual layer thicknesses ranging from 100 nm to 1.26 μm have been electrodeposited in the recirculating electrochemical flow reactor. The layer thicknesses were precisely controlled by adjusting the amount of charge passed.

Microtomy of spherical Al2O3 powders

1983 ◽  
Vol 41 ◽  
pp. 74-75
Author(s):  
E.J. Jenkins ◽  
D.S. Tucker ◽  
J.J. Hren
Keyword(s):  
Thin Film ◽  
Size Range ◽  
Particle Aggregation ◽  
Ion Milling ◽  
Thin Sections ◽  
Α Phase ◽  
Convenient Means ◽  
Van Der Waals Attraction ◽  
Negative Feature ◽  
Film Substrate

The size range of mineral and ceramic particles of one to a few microns is awkward to prepare for examination by TEM. Electrons can be transmitted through smaller particles directly and larger particles can be thinned by crushing and dispersion onto a substrate or by embedding in a film followed by ion milling. Attempts at dispersion onto a thin film substrate often result in particle aggregation by van der Waals attraction. In the present work we studied 1-10 μm diameter Al2O3 spheres which were transformed from the amprphous state to the stable α phase.After the appropriate heat treatment, the spherical powders were embedded in as high a density as practicable in a hard EPON, and then microtomed into thin sections. There are several advantages to this method. Obviously, this is a rapid and convenient means to study the microstructure of serial slices. EDS, ELS, and diffraction studies are also considerably more informative. Furthermore, confidence in sampling reliability is considerably enhanced. The major negative feature is some distortion of the microstructure inherent to the microtoming operation; however, this appears to have been surprisingly small. The details of the method and some typical results follow.

Corrosion of Electronic and Magnetic Devices and Materials

1996 ◽  
Vol 451 ◽  
Author(s):  
Gerald S. Frankel
Keyword(s):  
Thin Film ◽  
Failure Modes ◽  
Galvanic Corrosion ◽  
Potential Drop ◽  
Magnetic Devices ◽  
Disk Structure ◽  
Magnetic Layers ◽  
Ohmic Potential Drop ◽  
Corrosion Problem ◽  
Corrosion Susceptibility

ABSTRACTCorrosion of thin film structures commonly used in electronic and magnetic devices is discussed. Typical failure modes are presented, and galvanic corrosion is discussed in some detail since it is one common problem with such devices. A graphical explanation for the determination of the ohmic potential drop during galvanic corrosion is presented. The corrosion problem of thin film disks is shown to have changed during the past ten years owing to changes in disk structure. The corrosion susceptibility of two antiferromagnetic alloys used for exchange coupling to soft magnetic layers is discussed.

scholarly journals Pitting Corrosion Resistance and Repassivation Behavior of C-Bearing Duplex Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 930 ◽  
Author(s):  
Hanme Yoon ◽  
Heon-Young Ha ◽  
Tae-Ho Lee ◽  
Sung-Dae Kim ◽  
Jae Hoon Jang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Galvanic Corrosion ◽  
Dual Phase ◽  
Corrosion Resistant ◽  
Grain Sizes ◽  
Α Phase ◽  
Pitting Corrosion Resistance ◽  
Corrosion Pits ◽  
Pit Initiation

The effects of C-substitution for part of the N content, on the pitting corrosion resistance and repassivation tendencies of duplex stainless steels (DSSs) were investigated. For this investigation, normal UNS S32205 containing N only (DSS-N) and the C-substituted DSS (DSS-NC) were fabricated. Microstructural analyses confirmed that the two DSSs had dual-phase microstructures without precipitates, and they possessed similar initial microstructure, including their grain sizes and phase fractions. Polarization and immersion tests performed in concentrated chloride solutions revealed that the DSS-NC was more resistant against stable pitting corrosion and possessed a higher repassivation tendency than the DSS-N. Furthermore, the corrosion pits initiated and propagated to a less corrosion resistant α phase. Polarization tests and corrosion depth measurements conducted in an HCl solution indicated that the DSS-NC exhibited lower galvanic corrosion rate between the α and γ phases than the DSS-N. Therefore, the growth rate of pit embryo was lowered in the DSS-NC, which shifted the potentials for the stable pit initiation and the pit extinction to the higher values.

Hot-Wire Deposited Amorphous Silicon Thin-Film Transistors

1996 ◽  
Vol 424 ◽  
Author(s):  
R. E. I. Schropp ◽  
K. F. Feenstra ◽  
C. H. M. Van Der Werf ◽  
J. Holleman ◽  
H. Meiling
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Current Crowding ◽  
Hot Wire ◽  
Saturation Regime ◽  
Silicon Thin Film ◽  
Order Of Magnitude

AbstractWe present the first thin film transistors (TFTs) incorporating a low hydrogen content (5 - 9 at.-%) amorphous silicon (a-Si:H) layer deposited by the Hot-Wire Chemical Vapor Deposition (HWCVD) technique. This demonstrates the possibility of utilizing this material in devices. The deposition rate by Hot-Wire CVD is an order of magnitude higher than by Plasma Enhanced CVD. The switching ratio for TFTs based on HWCVD a-Si:H is better than 5 orders of magnitude. The field-effect mobility as determined from the saturation regime of the transfer characteristics is still quite poor. The interface with the gate dielectric needs further optimization. Current crowding effects, however, could be completely eliminated by a H2 plasma treatment of the HW-deposited intrinsic layer. In contrast to the PECVD reference device, the HWCVD device appears to be almost unsensitive to bias voltage stressing. This shows that HW-deposited material might be an approach to much more stable devices.

PREPARATION AND CHARACTERIZATION OF Zr-DOPED TiN NANOFILM

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3455-3458
Author(s):  
ANPING LIU ◽  
YINFENG WANG ◽  
XUEHENG YANG
Keyword(s):  
Thin Film ◽  
Corrosion Resistance ◽  
Energy Level ◽  
Mixed Crystal ◽  
Energy Levels ◽  
Energy Band Structure ◽  
Reactive Magnetron ◽  
Tin Coating ◽  
New Energy

The Zr -doped TiN coating, a nanometer (Ti, Zr)N thin film, has been deposited by reactive magnetron sputtering on slides and Al substrates. The crystalline phase and energy band structure have been analyzed by XRD and STS. The results of XRD show that the (Ti, Zr)N film is poly crystalline and consisted of mixed crystal of TiN and ZrN phase. The STS spectra show that Zr -doping didn't change the position and band-gap of energy level, only two new energy levels appeared, Eg = 0.33eV and Eg = 0.42eV. According to the results of measurement, (Ti, Zr)N has higher hardness and better corrosion resistance than TiN by Zr -doping.

scholarly journals Effects of tungsten, chromium and zirconium on the corrosion behavior of ternary amorphous W–Cr–Zr alloys in 1 M NaOh solution

1970 ◽  
Vol 9 (9) ◽  
pp. 39-43
Author(s):  
Basu Ram Aryal ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Open Circuit Potential ◽  
Open Circuit ◽  
Corrosion Rates ◽  
Corrosion Resistance Property ◽  
Naoh Solution ◽  
Order Of Magnitude ◽  
Sputter Deposited ◽  
Zr Alloys

Simultaneous additions of tungsten, chromium and zirconium in the chromium- and zirconium-enriched sputter-deposited binary W-xCr and W-yZr are effective to improve the corrosion resistance property of the ternary amorphous W- xCr-yZr alloys after immersion for 240 h in 1 M NaOH solution open to air at 25°C. The corrosion rates of all the examined sputter-deposited (10-57)W-(18-42)Cr-(25-73)Zr alloys is higher than those of alloy-constituting elements (that is, tungsten, chromium and zirconium) in aggressive 1 M NaOH solution open to air at 25°C. The corrosion rates of all the examined sputter−deposited W–xCr–yZr alloys containing 10-57 at% tungsten, 18-42 at% chromium and 25-73 at% zirconium were in the range of 1.5-2.5 × 10−3 mm/y or lower which are more than two orders of magnitude lower than that of sputter-deposited tungsten and even about one order of magnitude lower than those of the sputter-deposited zirconium in 1 M NaOH solution. Keywords: Ternary W–Cr–Zr alloys; Amorphous; Corrosion rate; Open circuit potential; 1 M NaOH. DOI: http://dx.doi.org/10.3126/sw.v9i9.5516 SW 2011; 9(9): 39-43

scholarly journals A continuous net-like eutectic structure enhances the corrosion resistance of Mg alloys

2019 ◽  
Vol 5 (2) ◽  
pp. 49 ◽  
Author(s):  
Cijun Shuai ◽  
Wenjing Yang ◽  
Youwen Yang ◽  
Chengde Gao ◽  
Chongxian He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Eutectic Structure ◽  
Mg Alloys ◽  
The Other ◽  
Laser Melting ◽  
Α Phase ◽  
Az61 Alloy ◽  
Mg17al12 Phase ◽  
Good Biocompatibility ◽  
Ti Content

Mg alloys degrade rather rapidly in a physiological environment, although they have good biocompatibility andfavorable mechanical properties. In this study, Ti was introduced into AZ61 alloy fabricated by selective laser melting,aiming to improve the corrosion resistance. Results indicated that Ti promoted the formation of Al-enriched eutectic α phaseand reduced the formation of β-Mg17Al12 phase. With Ti content reaching to 0.5 wt.%, the Al-enriched eutectic α phaseconstructed a continuous net-like structure along the grain boundaries, which could act as a barrier to prevent the Mg matrixfrom corrosion progression. On the other hand, the Al-enriched eutectic α phase was less cathodic than β-Mg17Al12 phase inAZ61, thus alleviating the corrosion progress due to the decreased potential difference. As a consequence, the degradationrate dramatically decreased from 0.74 to 0.24 mg·cm-2·d-1. Meanwhile, the compressive strength and microhardness wereincreased by 59.4% and 15.6%, respectively. Moreover, the Ti-contained AZ61 alloy exhibited improved cytocompatibility.It was suggested that Ti-contained AZ61 alloy was a promising material for bone implants application.

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