Excitations, order parameters, and phase diagram of solid deuterium at megabar pressures

1995 ◽  
Vol 51 (21) ◽  
pp. 14987-14997 ◽  
Author(s):  
Lijing Cui ◽  
Nancy H. Chen ◽  
Isaac F. Silvera
Keyword(s):  
Phase Diagram ◽  
Order Parameters ◽  
Solid Deuterium

Phase Diagram and Component Order Parameters in a Nematic Mixture: A Combined Deuterium and Proton NMR Study

1986 ◽  
Vol 139 (3-4) ◽  
pp. 217-239 ◽  
Author(s):  
P. Esnault ◽  
F. Volino ◽  
M. M. Gauthier ◽  
A. M. Giroud-godquin
Keyword(s):  
Phase Diagram ◽  
Proton Nmr ◽  
Order Parameters ◽  
Nmr Study ◽  
Component Order

Separation of nematic and smectic-A potential effects on solute ordering in a series of binary 6OCB–8OCB mixtures

2011 ◽  
Vol 89 (7) ◽  
pp. 900-908 ◽  
Author(s):  
E. Elliott Burnell ◽  
Ronald Y. Dong ◽  
Adrian C.J. Weber ◽  
Xuan Yang ◽  
Anand Yethiraj
Keyword(s):  
Phase Diagram ◽  
Binary Mixture ◽  
Optical Microscopy ◽  
Absolute Magnitude ◽  
Order Parameters ◽  
The Novel ◽  
Temperature Range ◽  
H Nmr ◽  
Smectic A ◽  
Phase Sequence

1H NMR and optical microscopy have been used to study four solutes dissolved in samples of a binary mixture of 4-n-hexyloxy-4′-cyanobiphenyl (6OCB) and 4-n-octyloxy-4′-cyanobiphenyl (8OCB) that are close to the region of the phase diagram where the smectic-A (SmA) and re-entrant nematic (RN) phases exist. Optical microscopy clearly indicates that one of the four studied samples shows the phase sequence of isotropic–nematic–SmA–RN. The derived solute order parameters were interpreted by means of two Maier–Saupe mechanisms in conjunction with the Kobayashi–McMillan theory in the case of the SmA phase. The novel feature of this study is that the nematic potential is extrapolated from the nematic to the SmA phase based on concentrations of the 6OCB–8OCB mixtures. The derived smectic order parameters for each of the studied solutes clearly show a maximum absolute magnitude near the centre of the SmA temperature range. The different partitioning of these solutes in the binary mixture is also discussed.

THE METASTABLE PHASE DIAGRAM OF THE BLUME–EMERY–GRIFFITHS MODEL IN ADDITION TO THE EQUILIBRIUM PHASE DIAGRAM USING THE PAIR APPROXIMATION

2005 ◽  
Vol 19 (10) ◽  
pp. 1741-1755 ◽  
Author(s):  
AHMET ERDİNÇ ◽  
MUSTAFA KESKİN
Keyword(s):  
Phase Diagram ◽  
Metastable Phase ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Order Parameters ◽  
Second Order ◽  
Pair Approximation ◽  
Variation Method ◽  
Metastable Phase Diagram ◽  
Phase Boundaries

As a continuation of our previously published work, the metastable phase diagram of the Blume–Emery–Griffiths model with the arbitrary bilinear (J), biquadratic (K) and crystal field interaction (D) is presented in addition to the equilibrium phase diagram in (T/K, J/K) and (T/K, D/K) plane by using the pair approximation of the cluster variation method on a body centered cubic lattice. We also calculate the phase transitions for the unstable branches of order parameters. The calculated first- and second-order phase boundaries of the unstable branches of the order parameters are superimposed on the equilibrium phase diagram and metastable phase diagram. It is found that the metastable phase diagram and the first- and second-order phase boundaries for unstable branches of order parameters always exist at low temperatures, which are consistent with the experimental and theoretical works.

scholarly journals Негейзенберговский ферримагентик с одноионной анизотропией

2022 ◽  
Vol 64 (3) ◽  
pp. 337
Author(s):  
О.А. Космачев ◽  
Е.А. Ярыгина ◽  
Я.Ю. Матюнина ◽  
Ю.А. Фридман
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Exchange Interaction ◽  
Order Parameters ◽  
Easy Plane ◽  
Heisenberg Exchange ◽  
Ferrimagnetic Phase ◽  
Tensor Order ◽  
Plane Type

We have investigated the effect of single-ion anisotropy of the "easy plane" type on the phase states of a ferrimagnet with S = 1 and σ=1/2 sublattices and non-Heisenberg (bilinear and biquadratic in spins) exchange interaction for the sublattice with S = 1. It is shown that taking into account both the non-Heisenberg exchange interaction and the single-ion anisotropy of the sublattice with S = 1 leads to the realization of a phase with vector order parameters (ferrimagnetic phase) and a phase characterized by both vector and tensor order parameters (quadrupole-ferrimagnetic). It is shown that taking into account single-ion anisotropy changes the type of phase transition in comparison with an isotropic non-Heisenberg ferrimagnet. A phase diagram is constructed, and the condition for the compensation of the sublattice spins is determined.

Joint Evolution of Two Domany–Kinzel Cellular Automata

1997 ◽  
Vol 11 (10) ◽  
pp. 1245-1255 ◽  
Author(s):  
Emílio P. Gueuvoghlanian ◽  
Tânia Tomé
Keyword(s):  
Phase Diagram ◽  
Cellular Automata ◽  
Mean Field ◽  
Order Parameters ◽  
Pair Approximation ◽  
Two Systems ◽  
Joint Dynamics ◽  
Analytical Approaches ◽  
Joint Evolution ◽  
Mean Field Approximations

We analyze the joint dynamics of two systems each one evolving in time according to the Domany–Kinzel rules. Two prescriptions for the joint evolution are studied. We make analytical approaches, based on dynamical mean-field approximations at the level of three-site correlations, to obtain the phase diagram. Also, the susceptibilities associated with the order parameters are calculated by using a pair approximation.

scholarly journals Order Parameters and Phase Diagram of MultiferroicRMn2O5

2008 ◽  
Vol 100 (21) ◽  
Author(s):  
A. B. Harris ◽  
Amnon Aharony ◽  
Ora Entin-Wohlman
Keyword(s):  
Phase Diagram ◽  
Order Parameters

Calculation of theP–Tphase diagram of nitrogen using a mean field model

2017 ◽  
Vol 31 (31) ◽  
pp. 1750245 ◽  
Author(s):  
Y. Enginer ◽  
G. Algul ◽  
H. Yurtseven
Keyword(s):  
Phase Diagram ◽  
Molecular Nitrogen ◽  
Mean Field ◽  
Quadratic Function ◽  
Order Parameters ◽  
Free Energies ◽  
Mean Field Model ◽  
Phase Line ◽  
T Phase ◽  
Quadratic Coupling

The P–T phase diagram is calculated at low and moderate pressures by obtaining the phase line equations for the transitions considered in nitrogen using the Landau phenomenological model. For some transitions, a quadratic coupling between the order parameters is taken into account in the expansion of free energies in terms of the order parameters. A quadratic function in T and P is fitted to the experimental P–T data from the literature and the fitted parameters are determined.It is shown that the model studied here describes the observed data adequately, which can also be used to predict the thermodynamic properties of the phases of the molecular nitrogen within the temperatures and pressures of the P–T phase diagram of this system.

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