Initial Phase formation at the Interface of Ni, Pd, or Pt and Si

1983 ◽  
Vol 25 ◽  
Author(s):  
R. J. Nemanich ◽  
C. C. Tsai ◽  
B. L. Stafford ◽  
J. R. Abelson ◽  
T. W. Sigmon
Keyword(s):  
Raman Spectroscopy ◽  
Phase Formation ◽  
Crystalline Phase ◽  
Initial Phase ◽  
Noble Metals ◽  
Kinetic Process ◽  
The Stability ◽  
Ion Backscattering

ABSTRACTThe initial phase formation at the interface of the near noble metals (Ni, Pd, and Pt) and Si is studied by Raman spectroscopy and Rutherford ion-backscattering. The results show that a crystalline Pd2Si forms immediately at the interface of Pd and Si while a disordered intermixed phase of composition ∼M2Si forms for Ni and Pt at 150°C. The results are discussed in terms of the disorder due to the kinetic process and the stability of the crystalline phase.

Aluminium-Transition Metal Thin-Film Reactions

1988 ◽  
Vol 119 ◽  
Author(s):  
E. G. Colgan ◽  
J. W. Mayer
Keyword(s):  
Thin Film ◽  
Transition Metal ◽  
Literature Review ◽  
Phase Diagrams ◽  
Phase Formation ◽  
Systematic Study ◽  
Initial Phase ◽  
Noble Metals ◽  
Rich Phase ◽  
Subsequent Phase

AbstractA systematic study of Al/metal reactions has been performed. The thin-film interactions of Al with refractory metals (Ti, V, Ta, Cr, Mo, W and Co) and near-noble metals (Ni, Pd, and Pt) have been investigated. The initial aluminide phases to grow are the Al-rich phases: TiAl3, Val3, TaAl3, Cr2Al13, MoAl12, Wal12, Co2Al9, NiAl3, Pd2Al3, and Pt2Al3 at temperatures between 225 and 525°C. With the exceptions of Val3, Pd2Al3, and Pt2Al3. these are the most Al-rich phases on the phase diagrams. Marker experiments were performed and Al was the dominant diffusing species during the growth of these phases, TiAl3, Val3, Cr2Al3, MoAl12, Co2Al2, NiAl3, Pd2Al3, and Pt2AI3. Consistent with the faster Al diffusion, which provides a greater supply of Al to the growing interface, is the growth of the most Al-rich phase initially. For the exceptions to this rule, Val3, Pd2AI3, and Pt2 Al3, the complexity of the Al-rich V, Pd, and Pt end phases may have hindered nucleation, resulting in the growth of the observed phases. The subsequent phase formation was examined in the Ni-, Pd-, and Pt-Al systems. After initial phase formation consumed all the Al or metal, subsequent phases formed in accordance with the overall stoichiometry. The results of this study, along with a brief literature review, are presented and the generalized behavior of Al/transition metal reactions discussed.

scholarly journals Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Ball Milling ◽  
Multiwalled Carbon Nanotubes ◽  
Tribological Properties ◽  
Extreme Pressure ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Gear Oil ◽  
The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

Crystalline phase formation in metakaolinite geopolymers activated with NaOH and sodium silicate

2009 ◽  
Vol 44 (17) ◽  
pp. 4668-4676 ◽  
Author(s):  
Bo Zhang ◽  
Kenneth J. D. MacKenzie ◽  
Ian W. M. Brown
Keyword(s):  
Sodium Silicate ◽  
Phase Formation ◽  
Crystalline Phase

scholarly journals Research on Periodic Motion Stability of Rotor-Bearing System with Dual-Unbalances

2011 ◽  
Vol 2-3 ◽  
pp. 728-732
Author(s):  
Chao Feng Li ◽  
Guang Chao Liu ◽  
Qin Liang Li ◽  
Bang Chun Wen
Keyword(s):  
Stability Analysis ◽  
Phase Difference ◽  
Periodic Motion ◽  
Initial Phase ◽  
Shooting Method ◽  
Small Eccentricity ◽  
Rotor Bearing ◽  
Large Eccentricity ◽  
The Stability ◽  
Bearing System

Multiple freedom degrees model of rotor-bearing system taking many factors into account is established, the Newmark-β and shooting method are combined during the stability analysis of periodic motion in such system. The paper focused on the influence law of two eccentric phase difference on the instability speed of rotor-bearing system. The results have shown that the instability speed rises constantly with the eccentric phase difference angle increasing in small eccentricity system. When the two unbalance be in opposite direction, the system reached its maximum instability speed. However, the unstable bifurcation generates mutation phenomenon for large eccentricity system with the eccentric phase difference angle increasing. In summary, the larger initial phase angle can inhibit system instability partly. The conclusions have provided a theoretical reference for vibration control and stability design of the more complex rotor-bearing system.

CO2 electrolysis – Complementary operando XRD, XAS and Raman spectroscopy study on the stability of CuxO foam catalysts

2020 ◽  
Vol 389 ◽  
pp. 592-603 ◽  
Author(s):  
Abhijit Dutta ◽  
Motiar Rahaman ◽  
Burkhard Hecker ◽  
Jakub Drnec ◽  
Kiran Kiran ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Spectroscopy Study ◽  
The Stability ◽  
Co2 Electrolysis

Influence of argon pressure on the crystalline phase formation of RF sputtered zinc sulfide thin films

2020 ◽  
Vol 29 ◽  
pp. 917-922
Author(s):  
S.R. Chalana ◽  
V.S. Kavitha ◽  
P. Srinivasan ◽  
S. Rafi Ahamed ◽  
Gargi Tiwari ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Sulfide ◽  
Phase Formation ◽  
Crystalline Phase ◽  
Argon Pressure
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