Structural Stability Diagrams for Thin-Film Multilayers

1997 ◽  
Vol 481 ◽  
Author(s):  
S. A. Dregia ◽  
R. Banerjee ◽  
H. L. Fraser
Keyword(s):  
Thin Film ◽  
Phase Diagram ◽  
Structural Stability ◽  
Phase Stability ◽  
Degrees Of Freedom ◽  
Two Degrees Of Freedom ◽  
Stability Diagrams ◽  
Interfacial Energies ◽  
New Type ◽  
Classical Thermodynamics

ABSTRACTStructural stability in thin-film multilayers is described in terms of classical thermodynamics, involving the competition between bulk and interfacial energies. A new type of phase diagram is introduced, the biphase diagram, in which concurrent phase stabilities are mapped as a function of two degrees of freedom, corresponding to two independent layer thicknesses in a periodic multilayer. The model is used to explain our observations of phase stabilities in Al/Ti multilayers, as a function of varying layer thicknesses. The model is also applied to explain the experimental observations made by other investigators on phase stability in Co/Cr thin-film multilayers.

On Mode Coupling Analysis and Stability Regions to Energy Harvesting in a Two-Degrees-of-Freedom Portal Frame Platform

2017 ◽  
Author(s):  
Rodrigo T. Rocha ◽  
Jose M. Balthazar ◽  
Angelo M. Tusset ◽  
Vinicius Piccirillo ◽  
Frederic C. Janzen ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Material ◽  
Internal Resonance ◽  
Degrees Of Freedom ◽  
Multiple Scales ◽  
Great Influence ◽  
Two Degrees Of Freedom ◽  
Stability Diagrams ◽  
Modal Coupling ◽  
Portal Frame

This work aims to study the modal coupling of a nonlinear two-degrees-of-freedom portal frame platform and a numerical analysis of the system with a nonlinear piezoelectric (PZT) material coupled to one of its columns, both externally base-excited. The nonlinear platform possesses two-to-one internal resonance between its two vibration modes and presenting the saturation phenomenon. The nonlinearities of the piezoelectric material are considered by a nonlinear mathematical relation. Here, it is considered an electro-dynamical shaker with harmonic output. The employed methodology to carry out the analysis of this work was: the application of the method of multiple scales to find the best configuration of the parameters, and to find some kind of phenomena due to the two-to-one internal resonance; several numerical simulations were carried out to optimize the energy harvesting through parametrical variations, bifurcation diagrams, stability diagrams. It will be analyzed: the influence of the nonlinearity of the piezoelectric material and of the electro-dynamical shaker on the energy harvesting. Results showed great influence of the nonlinearity of the material and using the electro-dynamical device. It was possible to gain considerably in energy harvesting and stability of the system.

Effect of Concentration Gradient on Phase Stability

1982 ◽  
Vol 19 ◽  
Author(s):  
K.N. Tu ◽  
U. GöSele
Keyword(s):  
Thin Film ◽  
Phase Diagram ◽  
Intermetallic Compound ◽  
Phase Stability ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Metal Films ◽  
Silicide Formation ◽  
Intermetallic Compound Growth ◽  
Form Alone

ABSTRACTA feature of thin film reaction that is different from the reaction in bulk samples is the tendency to form a single intermetallic compound rather than all of them which are allowed according to the equilibrium phase diagram. For example, in thin film silicide formation, Pd2Si has been found to form alone and to grow as a layer between Pd and Si. The silicide is stable over a wide temperature range of 100 to 700°C. The phenomenon of single intermetallic compound growth is not unique to silicide formation between transition metal films and silicon, but is also commonly observed in reactions between bimetallic thin films. The phenomenon indicates phase stability.

THERMODYNAMIC CALCULATION OF PHASE DIAGRAM AND PHASE STABILITY WITH NANO-SIZE PARTICLES

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2645-2650 ◽  
Author(s):  
XING JUN LIU ◽  
CUI PING WANG ◽  
JIAN ZHONG JIANG ◽  
IKUO OHNUMA ◽  
RYOSUKE KAINUMA ◽  
...  
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Phase Stability ◽  
Interfacial Energies ◽  
Pure Metals ◽  
Predicted Values ◽  
Fcc Phase ◽  
Size Of Particles ◽  
Nano Size ◽  
Good Agreement

In the present paper, the surface tensions and interfacial energies for pure metals and alloys for different structures were predicted by combining with the evaluated thermodynamic parameters in the framework of the CALPHAD (Calculation of Phase Diagrams) method. It is shown that the calculated results are in good agreement with the existing experimental data. On the basis of the predicted values of surface tension and interfacial energy, the phase stability and phase diagram with nano-size particles can be calculated by considering the Gibbs-Thomson equation. The calculated results for pure Fe indicate that the fcc phase is more stable with the decreasing of size of particles, which is in agreement with the experimental data reported, and the phase diagram with nano-size particle can be calculated.

scholarly journals Phase Stability Diagrams for Nanostructured Thin Film Multilayers

2003 ◽  
Vol 9 (S02) ◽  
pp. 292-293
Author(s):  
G. B. Thompson ◽  
R. Banerjee ◽  
H. L. Fraser
Keyword(s):  
Thin Film ◽  
Phase Stability ◽  
Stability Diagrams ◽  
Nanostructured Thin Film

Effective Interactions Approach to Phase Stability in Alloys Under Irradiation

1998 ◽  
Vol 538 ◽  
Author(s):  
Raúl A. Enrique ◽  
Pascal Bellon
Keyword(s):  
Phase Diagram ◽  
Phase Stability ◽  
Kinetic Monte Carlo ◽  
Theoretical Frameworks ◽  
Effective Interactions ◽  
Dynamical Phase ◽  
Thermodynamic Potentials ◽  
Simple Kinetic Model ◽  
Kinetic Monte Carlo Simulations ◽  
Competing Dynamics

AbstractPhase stability in alloys under irradiation is studied considering effective thermodynamic potentials. A simple kinetic model of a binary alloy with phase separation is investigated. Time evolution in the alloy results from two competing dynamics: thermal diffusion, and irradiation induced ballistic exchanges. The dynamical (steady state) phase diagram is evaluated exactly performing Kinetic Monte Carlo simulations. The solution is then compared to two theoretical frameworks: the effective quasi-interactions model as proposed by Vaks and Kamishenko, and the effective free energy model as proposed by Martin. New developments of these models are proposed to allow for quantitative comparisons. Both theoretical frameworks yield fairly good approximations to the dynamical phase diagram.

The scientific bases of autocontrol with vibration phase for a resonance beating-vibration system with two degrees of freedom driven by debalances

1996 ◽  
Vol 18 (2) ◽  
pp. 43-48
Author(s):  
Tran Van Tuan ◽  
Do Sanh ◽  
Luu Duc Thach
Keyword(s):  
Degrees Of Freedom ◽  
Regulation System ◽  
Vibration System ◽  
Two Degrees Of Freedom ◽  
System Operating

In the paper it is introduced a method for studying dynamics of beating-vibrators by means of digital calculation with the help of the machine in accordance with the needs by the helps of an available auto regulation system operating with high reability.

scholarly journals Two Degrees of Freedom Slip Controller with Lateral Torque Distribution

2020 ◽  
Vol 53 (2) ◽  
pp. 14450-14455
Author(s):  
Wolfgang Degel ◽  
Stefan Lupberger ◽  
Dirk Odenthal ◽  
Naim Bajcinca
Keyword(s):  
Degrees Of Freedom ◽  
Torque Distribution ◽  
Two Degrees Of Freedom
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