scholarly journals Deposition and Properties of Amorphous TiBN/AlCrYN Multilayer Coatings with Various Modulation Periods

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Wei Dai ◽  
Fan Liu ◽  
Qimin Wang
Keyword(s):  
Amorphous Structure ◽  
Oxidation Temperature ◽  
Diffusion Control ◽  
Multilayer Coatings ◽  
X Ray Diffraction ◽  
Outward Diffusion ◽  
Modulation Period ◽  
Thermogravimetric Analyzer ◽  
Coating Surface ◽  
Aluminum Oxide Layer

In this paper, multilayer coatings consisted of amorphous AlCrYN layers and TiBN layers were deposited by the cosputtering technique. The influence of the modulation period of the multilayer coatings on the structure, mechanical properties, and oxidation behavior of the coatings was studied carefully by using scanning electron microscope, X-ray diffraction, nanoindentation, scratch tester, and thermogravimetric analyzer. The results show that the TiBN/AlCrYN multilayer coatings exhibit an amorphous structure without any feature. Decreasing the modulation period could significantly improve the coating hardness and elastic modulus. In addition, the adhesion of the multilayer coatings could be enhanced as the modulation period decreases. At relative low oxidation temperature (≤900°C), a dense aluminum oxide layer formed on the coating surface can effectively hinder the inward diffusion of O and the outward diffusion of metal elements. The oxidation behaviors of the TiBN/AlCrYN multilayer coatings obeyed the diffusion control law. The oxidation resistance of the coatings was increasing with decreasing the modulation period since the interfaces of multilayer structures would block the diffusion of elements. At relative high oxidation temperature (1000°C), however, the coating surface was rapidly oxidized into the porous TiO2 whiskers rather than the dense Al2O3 layer, resulting in the inward diffusion of O and thus causing the serious oxidation of the coatings.

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

Influences of modulation period on structure and properties of AlTiSiN/AlCrSiN nanocomposite multilayer coatings

Vacuum ◽  
2021 ◽  
pp. 110516
Author(s):  
Y. Liu ◽  
H.D. Liu ◽  
Vasiliy Pelenovich ◽  
Q. Wan ◽  
J.L. Guo ◽  
...  
Keyword(s):  
Multilayer Coatings ◽  
Structure And Properties ◽  
Modulation Period

Structure and Electrochemical Behavior of Plasma-Sprayed LSGM Electrolyte Films

2002 ◽  
Vol 756 ◽  
Author(s):  
H. Zhang ◽  
X. Ma ◽  
J. Dai ◽  
S. Hui ◽  
J. Roth ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Amorphous Structure ◽  
Solid Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Electrolyte Film ◽  
Plasma Sprayed

ABSTRACTAn intermediate temperature solid oxide fuel cell (SOFC) electrolyte film of La0.8Sr 0.2Ga0.8Mg0.2O2.8 (LSGM) was fabricated using a plasma spray process. The microstructure and phase were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the thermal sprayed LSGM film was investigated using electrochemical impedance spectroscopy (EIS). The study indicates that thermal spray can deposit a dense LSGM layer. It was found that the rapid cooling in the thermal process led to an amorphous or poor crystalline LSGM deposited layer. This amorphous structure has a significant effect on the performance of the cell. Crystallization of the deposited LSGM layer was observed during annealing between 500–600 °C. After annealing at 800 °C, the ionic conductivity of the sprayed LSGM layer can reach the same level as that of the sintered LSGM.

scholarly journals Investigation and Modeling of the Electrical Conductivity of Graphene Nanoplatelets-Loaded Doped-Polypyrrole

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1034
Author(s):  
Oladipo Folorunso ◽  
Yskandar Hamam ◽  
Rotimi Sadiku ◽  
Suprakas Sinha Ray ◽  
Neeraj Kumar
Keyword(s):  
Electrical Conductivity ◽  
Structural Changes ◽  
Spherical Shape ◽  
Graphene Nanoplatelets ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Energy Storage Applications ◽  
Electrical Conductivity Data

In this study, a hybrid of graphene nanoplatelets with a polypyrrole having 20 wt.% loading of carbon-black (HGPPy.CB20%), has been fabricated. The thermal stability, structural changes, morphology, and the electrical conductivity of the hybrids were investigated using thermogravimetric analyzer, differential scanning calorimeter, X-ray diffraction analyzer, scanning electron microscope, and laboratory electrical conductivity device. The morphology of the hybrid shows well dispersion of graphene nanoplatelets on the surface of the PPy.CB20% and the transformation of the gravel-like PPy.CB20% shape to compact spherical shape. Moreover, the hybrid’s electrical conductivity measurements showed percolation threshold at 0.15 wt.% of the graphene nanoplatelets content and the curve is non-linear. The electrical conductivity data were analyzed by comparing different existing models (Weber, Clingerman and Taherian). The results show that Taherian and Clingerman models, which consider the aspect ratio, roundness, wettability, filler electrical conductivity, surface interaction, and volume fractions, closely described the experimental data. From these results, it is evident that Taherian and Clingerman models can be modified for better prediction of the hybrids electrical conductivity measurements. In addition, this study shows that graphene nanoplatelets are essential and have a significant influence on the modification of PPy.CB20% for energy storage applications.

Material Characteristics and Electrical Modeling of Ultra Thin Copper Oxides in ULSI Application

2007 ◽  
Vol 561-565 ◽  
pp. 1225-1228
Author(s):  
Takayuki Ohba
Keyword(s):  
Diffraction Pattern ◽  
Barrier Height ◽  
Oxide Thickness ◽  
Amorphous Structure ◽  
Emission Model ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Current Emission ◽  
X Ray Absorption

With the highest brilliance synchrotron radiation X-ray (SPring-8) and TEM observations, Cu oxides ranged 2-nm to 10-nm in thickness formed on sputtered Cu has been evaluated. For the plasma-assisted Cu oxide, weak Cu2O and/or CuO X-ray diffraction pattern is observed, while no diffraction pattern in native and thermally (170°C) grown oxides. Those native and thermal oxides show Cu2O coordination observed by XANES (X-ray Absorption Near Edge Structure) method. This suggests that Cu oxide formed at low temperatures consists of stoichiometric Cu2O in an amorphous structure. According to the Fowler-Nordheim (F-N) current emission model, the current emission taking place at Cu2O decreases with increasing of the oxide thickness and its mean barrier height (φB) in the MIM band structure. In case of current density at 106A/cm2 of 1V, it is estimated that the allowable thickness of Cu oxides is approximately 1.5-nm at 1 eV of barrier height.

Study on the Oxidation and Spontaneous Combustion Characteristics of Jurassic Coal in North Shaanxi

2014 ◽  
Vol 977 ◽  
pp. 124-128 ◽  
Author(s):  
Jun Deng ◽  
Kai Wang ◽  
Xiao Wei Zhai
Keyword(s):  
Functional Groups ◽  
Spontaneous Combustion ◽  
Combustion Process ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
High Oxygen Content ◽  
Ether Oxygen ◽  
Jurassic Coal ◽  
Proximate And Ultimate Analysis ◽  
Low Sulfur

Proximate and ultimate analysis, X-ray diffraction, infrared spectroscopy and thermal analysis experiments were carried out to study the spontaneous combustion oxidation based characteristic of six Jurassic coal samples from North Shaanxi in West China and three Permo-carboniferous coal samples from East China. The results showed that the characteristic of north Shaanxi Jurassic coal was low ash, low sulfur, high volatile, high oxygen content and amorphous structure. More type and quantity of reactive functional groups existed in the original Jurassic coal, such as carboxyl, methyl, methylene and ether oxygen. And the characteristic temperatures of north Shaanxi Jurassic coal sample in the oxidation and spontaneous combustion process was lower than other coal samples, due to the participation in the reaction with oxygen of the more active functional groups.

Facile hydrothermal synthesis of Fe3O4 nanoparticle and effect of crystallinity on performances for supercapacitor

2019 ◽  
Vol 12 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Yue Xu ◽  
Ying Zhang ◽  
Xiaolan Song ◽  
Hanjun Liu
Keyword(s):  
Hydrothermal Method ◽  
Reaction Times ◽  
Amorphous Structure ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Oxide Electrode ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Pseudocapacitive Behavior ◽  
Adsorption Desorption

Fe3O4 nanoparticles were synthesized by a facile hydrothermal method using triethanolamine. Effects of reaction times (2–8[Formula: see text]h) on crystallinity and electrochemical performances of Fe3O4 were investigated. Samples were analyzed by X-ray diffraction, infrared spectroscopy, N2 adsorption–desorption, scanning electron microscope, galvanostatic charge/discharge, and cyclic voltammetry. Results showed that the crystallinity of Fe3O4 was increased with hydrothermal time, and the sample prepared at 2[Formula: see text]h displayed amorphous structure with small grain size and large surface area of 165.0[Formula: see text]m2[Formula: see text]g[Formula: see text]. The sample exhibited typical pseudocapacitive behavior with capacitance of 383.2[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5 Ag[Formula: see text] in Na2SO3 electrolyte. After 2000 cycles, the capacitance retention of Fe3O4 at 2[Formula: see text]h was recorded as 83.6%, much higher than 26.3% for sample at 8[Formula: see text]h. It indicated that hydrothermal method was an effective approach to obtain amorphous Fe3O4, implying the potential application for preparing metal oxide electrode for supercapacitors.

Effect of Substrate Temperature on the Electrochromic Properties of Cobalt Hydroxide Thin Films Prepared by Reactive Sputtering

2011 ◽  
Vol 1328 ◽  
Author(s):  
KyoungMoo Lee ◽  
Yoshio Abe ◽  
Midori Kawamura ◽  
Hidenobu Itoh
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Indium Tin Oxide ◽  
Large Change ◽  
Amorphous Structure ◽  
Cobalt Hydroxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Substrate Temperatures

ABSTRACTCobalt hydroxide thin films with a thickness of 100 nm were deposited onto glass, Si and indium tin oxide (ITO)-coated glass substrates by reactively sputtering a Co target in H2O gas. The substrate temperature was varied from -20 to +200°C. The EC performance of the films was investigated in 0.1 M KOH aqueous solution. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy of the samples indicated that Co3O4 films were formed at substrate temperatures above 100°C, and amorphous CoOOH films were deposited in the range from 10 to -20°C. A large change in transmittance of approximately 26% and high EC coloration efficiency of 47 cm2/C were obtained at a wavelength of 600 nm for the CoOOH thin film deposited at -20°C. The good EC performance of the CoOOH films is attributed to the low film density and amorphous structure.

scholarly journals A Study on the Characteristics of Cu–Mn–Dy Alloy Resistive Thin Films

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 118 ◽  
Author(s):  
Ho-Yun Lee ◽  
Chi-Wei He ◽  
Ying-Chieh Lee ◽  
Da-Chuan Wu
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
Transmission Electronmicroscopy ◽  
Scanning Electron

Cu–Mn–Dy resistive thin films were prepared on glass and Al2O3 substrates, which wasachieved by co-sputtering the Cu–Mn alloy and dysprosium targets. The effects of the addition ofdysprosium on the electrical properties and microstructures of annealed Cu–Mn alloy films wereinvestigated. The composition, microstructural and phase evolution of Cu–Mn–Dy films werecharacterized using field emission scanning electron microscopy, transmission electronmicroscopy and X-ray diffraction. All Cu–Mn–Dy films showed an amorphous structure when theannealing temperature was set at 300 °C. After the annealing temperature was increased to 350 °C,the MnO and Cu phases had a significant presence in the Cu–Mn films. However, no MnO phaseswere observed in Cu–Mn–Dy films at 350 °C. Even Cu–Mn–Dy films annealed at 450 °C showedno MnO phases. This is because Dy addition can suppress MnO formation. Cu–Mn alloy filmswith 40% dysprosium addition that were annealed at 300 °C exhibited a higher resistivity of ∼2100 μΩ·cm with a temperature coefficient of resistance of –85 ppm/°C.

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