Estimating Relative Stability of Polymorphs by Generation of Configurational Free Energy Phase Diagram

2012 ◽  
Vol 101 (5) ◽  
pp. 1843-1851 ◽  
Author(s):  
Pratik Upadhyay ◽  
Ajay K. Dantuluri ◽  
Lokesh Kumar ◽  
Arvind K. Bansal
Keyword(s):  
Phase Diagram ◽  
Free Energy ◽  
Relative Stability

WETTING AND PREWETTING PHENOMENA IN NEMATIC LIQUID CRYSTAL DISK-LIKE DROPLET

2019 ◽  
Vol 26 (04) ◽  
pp. 1850171
Author(s):  
ERFAN KADIVAR ◽  
SHAHRAM AHMADI DARANI
Keyword(s):  
Differential Equation ◽  
Boundary Layer ◽  
Phase Diagram ◽  
Free Energy ◽  
Liquid Crystal ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Critical Droplet ◽  
Quadratic Surface ◽  
Maxwell Construction

We present a theoretical investigation of wetting and prewetting phenomena in a nematic-disk like droplet under a concentric anchoring configuration. Our theoretical model is based on Landau–de Gennes free energy together with a quadratic surface energy. By using the Maxwell construction, we numerically solve the Euler–Lagrange differential equation. The occurrence of boundary layer transition is summarized in the phase diagram scanned by temperature and surface potential. We find that prewetting phenomenon disappear below a critical droplet size and critical temperature.

Phase diagrams of Ni2+xMn1-xGa Heusler alloys from Hubbard Hamiltonian with account of Jahn-Teller effect

2011 ◽  
Vol 1310 ◽  
Author(s):  
Mikhail A. Zagrebin ◽  
Vasiliy D. Buchelnikov ◽  
Sergey V. Taskaev ◽  
Natal’ya Yu. Fedulova
Keyword(s):  
Phase Diagram ◽  
Free Energy ◽  
Phase Transitions ◽  
Phase Diagrams ◽  
Density Of States ◽  
Heusler Alloys ◽  
Teller Effect ◽  
Hubbard Hamiltonian ◽  
Jahn Teller ◽  
Jahn Teller Effect

ABSTRACTIn this work a microscopic Hamiltonian is investigated using the Hubbard model for a ferromagnet with two degenerate bands, taking into account the Jahn-Teller effect. A macroscopic free energy is obtained from the microscopic Hubbard Hamiltonian. All free energy coefficients depend on microscopic parameters: temperature T and composition x. As a result of analytical minimization of free energy, phase diagrams are numerically constructed. It is shown that at certain values of parameters on the phase diagrams there are thermodynamic paths which correspond to experimentally observed sequences of phase transitions. Using density of states spectra for different compositions x the T-x phase diagram is numerically constructed. This phase diagram can theoretically explain experimentally observed behavior of the temperatures of phase transitions.

The rubidium chloride – sodium chloride phase diagram

1970 ◽  
Vol 48 (22) ◽  
pp. 3483-3486 ◽  
Author(s):  
A. D. Pelton ◽  
S. N. Flengas
Keyword(s):  
Phase Diagram ◽  
Free Energy ◽  
Sodium Chloride ◽  
Excess Entropy ◽  
Excess Free Energy ◽  
Thermochemical Data ◽  
Cooling Curves ◽  
Molar Excess ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

The phase diagram of the RbCl–NaCl system has been measured by the method of cooling curves. By combining these data with available thermochemical data for the system, the integral molar excess free energy of mixing at 800 °C has been calculated as ΔGE = −632XRbClXNaCl cal/mole; and the integral molar excess entropy of mixing has been calculated as ΔSE = −0.208XRbClXNaCl cal/°K mole. Estimated precisions are ±50 cal for ΔGE and ±0.05 cal/°K mole for ΔSE at XRbCl = XNaCl = 0.5.

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