Phase Transformation of Mo and W over Co OR Its Alloy in Contact with Si

1993 ◽  
Vol 311 ◽  
Author(s):  
Fann-Mei Yang ◽  
Mao-Chieh Chen
Keyword(s):  
Phase Transformation ◽  
Electron Beam ◽  
Metal Oxide ◽  
Base Pressure ◽  
Annealing Conditions ◽  
Higher Temperature ◽  
Ellingham Diagram

ABSTRACTW or Mo directly deposited on Si cold substrate by electron-beam gun at a base pressure of 10-6 torr is not able to form silicide even annealed at 900 °C in either N2 or H2 ambient. We present an easy way that Mo and W silicides can be formed on the same depositing and annealing conditions with the help of an intervened layer of cobalt or its alloy. Investigation was made on various metallizations of Mo (or W)/Co/Si, W/Co-Mo/Si, and Co/Mo/Si in normal flowingnitrogen or in H2 ambient at various temperatures. In the systems of Mo (or W)/Co/Si and W/Co-Mo/Si, the overlying Mo (or W) can be transformed into silicide at 900 °C, while in the Co/Mo/Si system, where stable Co-Mo compounds are formed in advance, no silicide can be formed. Why silicide is formed in preference to metal oxide in N2 environment at higher temperature is based on Ellingham diagram.

Effect of copper incorporation on phase transformation behavior of electroless nickel–phosphorous coating and its effect on the tribological behavior

2020 ◽  
pp. 146442072098160
Author(s):  
Abhijit Biswas ◽  
Suman Kalyan Das ◽  
Prasanta Sahoo
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Tribological Behavior ◽  
Electroless Nickel ◽  
Two Phase ◽  
Microstructural Changes ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Higher Temperature ◽  
Effect Of Copper

The microstructural changes of electroless Ni–P–Cu coating at various heat-treatment conditions are investigated to understand its implications on the tribological behavior of the coating. Coatings are heat-treated at temperatures ranging between 200°C and 800 °C and for 1–4 h duration. Ni–P–Cu coatings exhibit two-phase transformations in the temperature range of 350–450 °C and the resulting microstructural changes are found to significantly affect their thermal stability and tribological attributes. Hardness of the coating doubles when heat-treated at 452 °C, due to the formation of harder Ni3P phase and crystalline NiCu. Better friction and wear performance are also noted upon heat treatment of the coating at the phase transformation regime, particularly at 400 °C. Wear mechanism is characterized by a mixed adhesive cum abrasive wear phenomena. Heat treatment at higher temperature (600 °C and above) and longer duration (4 h) results in grain coarsening phenomenon, which negatively influences the hardness and tribological characteristics of the coating. Besides, diffusion of iron from the ferrous substrate as well as greater oxide formation are noticed when the coating is heat-treated at higher temperatures and for longer durations (4 h).

Selective electron beam melting of NiTi: Microstructure, phase transformation and mechanical properties

2019 ◽  
Vol 744 ◽  
pp. 290-298 ◽  
Author(s):  
Quan Zhou ◽  
Muhammad Dilawer Hayat ◽  
Gang Chen ◽  
Song Cai ◽  
Xuanhui Qu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Electron Beam ◽  
Electron Beam Melting ◽  
Selective Electron Beam Melting

Electron Microprobe and Photoluminescence Analysis of Europium-Doped Gallium Nitride Light Emitters

2002 ◽  
Vol 743 ◽  
Author(s):  
R. W. Martin ◽  
S. Dalmasso ◽  
K. P. O'Donnell ◽  
Y. Nakanishi ◽  
A. Wakahara ◽  
...  
Keyword(s):  
Electron Beam ◽  
Rare Earth ◽  
Visible Region ◽  
Depth Profiling ◽  
Luminescence Spectra ◽  
Light Emitters ◽  
Doping Density ◽  
Annealing Conditions ◽  
Electron Transitions ◽  
Doped Glass

ABSTRACTRare-earth doped GaN structures offer potential for optical devices emitting in the visible region [1,2]. We describe a study of MOVPE grown GaN-on-sapphire epilayers implanted with Europium ions, producing characteristic red emission lines between 540 and 680 nm due to intra-4f(n) electron transitions. As-implanted and subsequently annealed samples are investigated using a combination of wavelength dispersive x-ray analysis (WDX), electron microscopy, cathodoluminescence (CL) and photoluminescence (PL). WDX is shown to be a powerful technique for quantifying rare-earth concentrations in GaN, with varying electron beam voltages allowing a degree of depth profiling, further enhanced by the simultaneous collection of room temperature luminescence (CL) from the analysed region [3]. The intensities of the sharp lines observed in the luminescence spectrum are compared to the doping density (between 1014 – 1015 cm−2) and the Eu content measured by WDX, using a Eu-doped glass standard. Differences observed in the luminescence spectra produced by laser and electron beam excitation will be discussed along with the importance of the annealing conditions, which “heal” defects visible in the electron micrographs.

scholarly journals SPM—SEM Investigations of Semiconductor Nanowires for Integrated Metal Oxide Gas Sensors

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 701 ◽  
Author(s):  
Verena Leitgeb ◽  
Katrin Fladischer ◽  
Frank Hitzel ◽  
Florentyna Sosada-Ludwikowska ◽  
Johanna Krainer ◽  
...  
Keyword(s):  
Electron Beam ◽  
Metal Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Semiconductor Nanowires ◽  
Kelvin Probe ◽  
Sensor Applications ◽  
Sensitivity And Selectivity ◽  
Stable Performance ◽  
Metal Oxide Gas Sensors

Integration of metal oxide nanowires in metal oxide gas sensors enables a new generation of gas sensor devices, with increased sensitivity and selectivity. For reproducible and stable performance of next generation sensors, the electric properties of integrated nanowires have to be well understood, since the detection principle of metal oxide gas sensors is based on the change in electrical conductivity during gas exposure. We study two different types of nanowires that show promising properties for gas sensor applications with a Scanning Probe Microscope—Scanning Electron Microscope combination. Electron Beam Induced Current and Kelvin Probe Force Microscopy measurements with a lateral resolution in the nanometer regime are performed. Our work offers new insights into the dependence of the nanowire work function on its composition and size, and into the local interaction between electron beam and semiconductor nanowires.

The Correlation between the Reduction of Interface State Density at the SiO2/SiC Interface and the NO Post-Oxide-Annealing Conditions

2019 ◽  
Vol 954 ◽  
pp. 104-108
Author(s):  
Heng Yu Xu ◽  
Cai Ping Wan ◽  
Jin Ping Ao
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Interface State ◽  
State Density ◽  
Interface State Density ◽  
Mos Capacitors ◽  
Annealing Conditions ◽  
N Concentration ◽  
Higher Temperature ◽  
Secondary Ion

We fabricated SiO2/4H-SiC (0001) MOS capacitors with oxidation temperature at 1350°C, followed by post-oxide-annealing (POA) in NO simply by the control of POA temperatures and times. A correlation between the reduction of interface state density and the increasing of N concentration at the interface has been indicated by C-ψs measurement and secondary ion mass spectrometry (SIMS). The SiO2/4H-SiC interface density decreased when POA temperature was elevated, and the sample annealed at 1300°C for 30min showed the lowest interface state density about 1.5×1012 cm-2eV-1 at Ec-E=0.3 eV when the N concentration is 11.5×1020 cm-3. Meanwhile, the SiO2 /4H-SiC interface annealed at 1200°C for 120min showed the highest N concentration at the 4H-SiC/SiO2 interface is 12.5×1020 cm-3, whereas the interface state density is 2.5×1012 cm-2eV-1 at Ec-E=0.3 eV higher than 1300°C for 30min. The results suggested that higher temperature POA might be much more efficiency in decreased the 4H-SiC MOS interface density with increasing the N area concentration.

Phase transformation and characterization of TiO2 and ZrO2 addition in the Li2O–Al2O3-SiO2 gels

1996 ◽  
Vol 11 (10) ◽  
pp. 2611-2615 ◽  
Author(s):  
Ming-Hong Lin ◽  
Moo-Chin Wang
Keyword(s):  
Phase Transformation ◽  
Sol Gel ◽  
Peak Position ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
Ceramic Powders ◽  
Higher Temperature ◽  
Gel Technique ◽  
Dta Curves

Glass-ceramic powders with a composition of Li2O · Al2O3 · 4SiO2 (LAS) have been synthesized by the sol-gel technique using LiOCH3, Al(OC2H5)3, Si(OC2H5)4, Ti(OC2H5)4, and Zr(OC2H5)4 as starting materials and the phase transformation behavior during calcination has been investigated. Differential thermal analysis (DTA), x-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to determine the thermal behavior of the gels. Considering the LAS gels with 6.0 wt. % TiO2 and various wt. % ZrO2 content, and peak position of the β-spodumene phase formation in DTA curves was shifted to a higher temperature when the ZrO2 content was increased. The activation energy of β-spodumene crystallization was 283.8 kcal/mol for LAS gels with 6.0 wt. % TiO2 and 2.0 wt. % ZrO2. Unlike foregoing studies for LAS gels, during calcination of the dried LASTZ gels from 800 °C to 1200 °C neither β-eucryptite nor γ-spodumene was noted to be present. The crystallized phases comprised of β-spodumenes as the major phase and rutile (TiO2) together with zirconia (ZrO2) are precipitated as minor phases.

Synthesis and Dispersion of Ni-Doped Cu2ZnSnS4

2020 ◽  
Vol 860 ◽  
pp. 42-50
Author(s):  
Camellia Panatarani ◽  
Hera Redianti ◽  
Ferry Faizal ◽  
Eka Cahya Prima ◽  
Brian Yuliarto ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transformation ◽  
Zeta Potential ◽  
Elemental Analysis ◽  
High Energy ◽  
Future Application ◽  
Dispersing Agent ◽  
Higher Temperature ◽  
Average Size ◽  
Dispersing Agents

This paper reports the preliminary study on the synthesis of Ni doped CZTS (Cu2ZnSnS4:Ni) particle 5 at.% of Cu by solution method and dispersion of the obtained particles by beads mill method at various dispersing agents (SDS, CTAB, and Tween80). The phase transformation of the obtained particles was analyzed from the XRD spectra and XRF elemental analysis. The phase transformation and amount of Ni-doped to particles was predicted employing commercially available analytical software tool Match! Version 2.x. Moreover, the dispersion characteristics were investigated includes size, size distribution, and zeta potential of bare particles in comparison to various dispersing agents. This characteristic related to the future application of CZTS as an absorber in a thin-film based PV. The XRD analysis showed that the obtained particle contained crystal structure of copper sulfate pentahydrate (75.9 %), Ni(HN2S2)2 (12.5 %), and Cu2ZnSnS4 (11.6%). The XRF elemental analysis showed that amount of Ni-doped was 6.8 at.%; it was higher than the initial design amount of Ni doping. The dispersion of suspended particles was the majority (90%) with an average size of 3.06 µm and only 10 % with size 255 nm. Beads-milling of particles without dispersing agents did not disintegrate agglomerated particles. It is highlighted dispersion only using magnetic stirred with SDS dispersing agent provides the best suspension with a majority (60%) in 166 nm and only 30 % with average size 3.06 µm with relatively high zeta potential (-17 mV). It was concluded that the presence of a multi-phase crystal needs to be resolved either by proper calcination at a higher temperature than 400°C or further heating at a higher temperature during film preparation. High-energy centrifugation of zirconia beads mill caused desorption of adsorbed steric stabilization of dispersing agent under investigation. Further investigation on the coating process to facilitated laboratory fabrication of thin-film absorber with SDS as a dispersing agent is necessary to carry out concerning the properties of the thin-film.

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