scholarly journals SO(3) symmetry between Néel and ferromagnetic order parameters for graphene in a magnetic field

2007 ◽  
Vol 76 (8) ◽  
Author(s):  
Igor F. Herbut
Keyword(s):  
Magnetic Field ◽  
Order Parameters ◽  
Ferromagnetic Order

The Formation Energy of Martensite Nuclei and the Phase Transition Kinetics under the Action of an External Magnetic Field

2021 ◽  
Vol 410 ◽  
pp. 3-8
Author(s):  
Viktor N. Pustovoit ◽  
Yuri V. Dolgachev
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Initial Phase ◽  
Formation Energy ◽  
Martensite Phase ◽  
Nucleation Center ◽  
Austenite Matrix ◽  
Ferromagnetic Order ◽  
The Matrix ◽  
Phase Transition Kinetics

The formation energy of martensite nuclei in the austenite matrix is calculated. Nanoclusters with ferromagnetic order, which exist in austenite above the Curie temperature, reduce the formation energy of a critical martensite nucleation center when exposed to an external magnetic field. The data obtained are explained by the magnetic separation of the initial phase under the action of a magnetic field. A fluctuation increase in nanovolumes with a ferromagnetic order in austenite increases the energy in a atoms group of the matrix phase with a parallel spins arrangement. As a result, the nucleation rate of the martensite phase increases and the martensitic transformation proceeds more completely.

DYNAMIC PHASE TRANSITION IN THE KINETIC BLUME-EMERY-GRIFFITHS MODEL IN AN OSCILLATING EXTERNAL FIELD

2006 ◽  
Vol 17 (12) ◽  
pp. 1717-1737 ◽  
Author(s):  
OSMAN CANKO ◽  
ÜMİT TEMİZER ◽  
MUSTAFA KESKİN
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Stochastic Dynamics ◽  
Equations Of Motion ◽  
Order Parameters ◽  
Average Order ◽  
Dynamic Phase ◽  
Dynamic Phase Transition ◽  
Transition Points ◽  
Reduced Temperature

The dynamic phase transitions are studied, within a mean-field approach, in the kinetic Blume-Emery-Grifftihs model under the presence of a time varying (sinusoidal) magnetic field by using the Glauber-type stochastic dynamics and the set of the dynamic equations of motion is obtained. The behavior of the time-dependence of the order parameters and the behavior of the average order parameters in a period, which is also called the dynamic order parameters, as a function of the reduced temperature are investigated. The nature (continuous and discontinuous) of transition is characterized by studying the average order parameters in a period. The dynamic phase transition points are obtained and the phase diagrams are presented in the reduced magnetic field amplitude and reduced temperature plane. We have found that the behavior of system strongly depends on the interaction parameters and nine main different phase diagram topologies have been obtained. We also calculate the Liapunov exponents to verify the stability of the solutions and the dynamic phase transition points.

Ferromagnetic Order of Amorphous Fe-Ni-Zr Alloy Ribbons at Magnetic Field Below 10 kOe

2016 ◽  
Vol 30 (11) ◽  
pp. 3333-3338
Author(s):  
Tran Dang Thanh ◽  
N. H. Dan ◽  
N. H. Duc ◽  
T. L. Phan ◽  
V. H. Ky ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Ferromagnetic Order ◽  
Zr Alloy

scholarly journals Effect of Strong Magnetic Field on Competing Order Parameters in Two-Flavor Dense Quark Matter

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Tanumoy Mandal ◽  
Prashanth Jaikumar
Keyword(s):  
Magnetic Field ◽  
Strong Magnetic Field ◽  
Quark Matter ◽  
Critical Density ◽  
Weak Field ◽  
Phase Region ◽  
Order Parameters ◽  
Critical Ratio ◽  
Zero Field ◽  
Dense Quark Matter

We study the effect of strong magnetic field on competing chiral and diquark order parameters in a regime of moderately dense quark matter. The interdependence of the chiral and diquark condensates through nonperturbative quark mass and strong coupling effects is analyzed in a two-flavor Nambu-Jona-Lasinio (NJL) model. In the weak magnetic field limit, our results agree qualitatively with earlier zero-field studies in the literature that find a critical coupling ratioGD/GS~1.1below which chiral or superconducting order parameters appear almost exclusively. Above the critical ratio, there exists a significant mixed broken phase region where both gaps are nonzero. However, a strong magnetic fieldB≳1018 G disrupts this mixed broken phase region and changes a smooth crossover found in the weak-field case to a first-order transition for both gaps at almost the same critical density. Our results suggest that in the two-flavor approximation to moderately dense quark matter strong magnetic field enhances the possibility of a mixed phase at high density, with implications for the structure, energetics, and vibrational spectrum of neutron stars.

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