Polymorphic phase transition for inverse-power-potential crystals keeping the first-order anharmonic correction to the free energy

1994 ◽  
Vol 49 (5) ◽  
pp. 3043-3048 ◽  
Author(s):  
Daniel H. E. Dubin ◽  
Hugh Dewitt
Keyword(s):  
Phase Transition ◽  
Free Energy ◽  
Inverse Power ◽  
Polymorphic Phase Transition ◽  
First Order ◽  
Anharmonic Correction

TEMPERATURE DEPENDENCE OF SURFACE TENSION OF LIQUID CRYSTALS AT THE PHASE TRANSITION

1995 ◽  
Vol 09 (03n04) ◽  
pp. 237-242 ◽  
Author(s):  
R. MOLDOVAN ◽  
M. TINTARU ◽  
T. BEICA ◽  
S. FRUNZA ◽  
D. N. STOENESCU
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Surface Tension ◽  
Free Energy ◽  
Surface Layer ◽  
Order Parameter ◽  
Unit Area ◽  
Negative Slope ◽  
First Order ◽  
First Order Transition

The surface tension is calculated as the excess of the free energy per unit area, due to the presence of a surface layer, using Landau–de Gennes expansions, in the hypothesis of a first order transition in the bulk and taking into account the dependence of the surface free energy from the surface tilt angle. The surface order parameter is calculated and surface-ordered phase above the phase transition temperature has been found. A variety of calculated surface tension versus temperature curves with a jump at the phase transition, with positive or negative slope, well describing the experimental data from literature, have been attained.

Effect of Strain on Barium Titanate Epitaxial Films

2013 ◽  
Vol 547 ◽  
pp. 139-144
Author(s):  
Lye Hock Ong ◽  
A.M. Alrub ◽  
Khian Hooi Chew
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Free Energy ◽  
Epitaxial Films ◽  
Ferroelectric Films ◽  
Eighth Order ◽  
First Order ◽  
First Order Phase Transition ◽  
Highly Strained ◽  
First Order Phase

Landau-Ginzburg free energy expression with the normalized coefficients is used to elucidate the phase transition properties of strained ferroelectric films. In particular, we investigate the need to include higher order free energy terms for epitaxial strained BaTiO3 thin films. Our study reveals that the inclusion of eighth-order expression into the free energy is crucial in determining the phase transition of highly-strained BaTiO3 epitaxial films normally grown on thick cubic substrates. The phase transition is found to be second order but the unstrained film undergoes the first order phase transition. On the order hand, the calculation based on the usual sixth-order Landau-Ginzburg expression show that the films have no phase transition, which is contrary to the experimental observations.

scholarly journals Free-energy analysis of the nonhysteretic first-order phase transition of Eu2In

2020 ◽  
Vol 102 (13) ◽  
Author(s):  
B. P. Alho ◽  
P. O. Ribeiro ◽  
P. J. von Ranke ◽  
F. Guillou ◽  
Y. Mudryk ◽  
...  
Keyword(s):  
Phase Transition ◽  
Free Energy ◽  
Order Phase Transition ◽  
Energy Analysis ◽  
First Order ◽  
First Order Phase Transition ◽  
Free Energy Analysis ◽  
First Order Phase

SPONTANEOUS SYMMETRY BREAKING AND FIRST-ORDER PHASE TRANSITIONS OF ADSORBED FLUIDS

2010 ◽  
Vol 20 (02) ◽  
pp. 287-295 ◽  
Author(s):  
SALVADOR A. SARTARELLI ◽  
LESZEK SZYBISZ ◽  
IGNACIO URRUTIA
Keyword(s):  
Phase Transition ◽  
Free Energy ◽  
Symmetry Breaking ◽  
Density Functional ◽  
Spontaneous Breaking ◽  
Functional Formalism ◽  
Density Profiles ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase

A density functional formalism is applied to investigate the wetting behavior of Ne confined in slits composed of two parallel solid identical alkaline walls with increasing attractive strength leading to a variety of wetting situations. The study is performed over the complete range of temperature spanned from the triple point Tt up to the critical one Tc of Ne. Attention is paid to the slit's width. It was found that in the case of weaker substrates for temperatures below a certain critical Tsb the density profiles corresponding to the lowest free energy are asymmetric, i.e. exhibit a spontaneous breaking of symmetry. For T > Tsb the phenomenon of symmetry breaking disappears leading to a first-order phase transition.

Epitaxial Free Energy and Stability under Epitaxial Strain

1998 ◽  
Vol 05 (05) ◽  
pp. 983-988 ◽  
Author(s):  
P. M. Marcus
Keyword(s):  
Phase Transition ◽  
Free Energy ◽  
Order Phase Transition ◽  
Tetragonal Phase ◽  
First Order ◽  
Epitaxial Strain ◽  
First Order Phase Transition ◽  
The Stability ◽  
First Order Phase ◽  
Stability Limits

First-principles ground-state total-energy calculations show that tetragonal crystals generally have two structures at which the energy is a minimum, which are appropriately called tetragonal phases in equilibrium. The calculations also show that a small isotropic two-dimensional (epitaxial) strain in the basal plane of a tetragonal phase produces a first-order phase transition to another tetragonal phase, By defining and calculating a special free energy for the states produced by epitaxial strain, the stability limits of each phase and the occurrence of a first-order phase transition between them are clearly demonstrated. Epitaxially strained states and the epitaxial free energy are calculated for vanadium. The epitaxial free energy as a function of the epitaxial stress for these strained states is shown to be similar to free-energy curves calculated for other first-order phase transitions which have analytic descriptions.

scholarly journals Metashooting: a novel tool for free energy reconstruction from polymorphic phase transition mechanisms

2018 ◽  
Vol 211 ◽  
pp. 235-251
Author(s):  
Samuel Alexander Jobbins ◽  
Salah Eddine Boulfelfel ◽  
Stefano Leoni
Keyword(s):  
Phase Transition ◽  
Free Energy ◽  
Surface Reconstruction ◽  
Energy Surface ◽  
Free Energy Surface ◽  
Polymorphic Phase Transition ◽  
Energy Reconstruction ◽  
Transformation Mechanisms ◽  
Simulation Scheme

Metashooting, a novel simulation scheme, combines free energy surface reconstruction and detailed elucidation of transformation mechanisms.

Dissociative Phase Transitions, Split Shock Waves, Rarefaction Shocks, and Detonations

1992 ◽  
Vol 296 ◽  
Author(s):  
C. T. White ◽  
D. H. Robertson ◽  
M. L. Elert ◽  
J. W. Mintmire ◽  
D. W. Brenner
Keyword(s):  
Phase Transition ◽  
Shock Waves ◽  
Comparative Study ◽  
Continuum Theory ◽  
The Other ◽  
Polymorphic Phase Transition ◽  
Von Neumann ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase

AbstractWe present a comparative study of two different chemically-sustained shock waves. One shows behavior expected from the Zel'dovich, von Neumann, and Doering (ZND) continuum theory of planar detonations. The other exhibits the complexity of a split shock wave resulting from the presence of a polymorphic phase transition. This comparative study demonstrates the importance of carefully considering the high-pressure characteristics of the model in developing potentials for simulating detonations. This comparative study also raises the fascinating possibility of a first-order phase transition accompanying a condensed-phase detonation.

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