scholarly journals Magnetization of Rare Earth Materials

1974 ◽  
Vol 27 (1) ◽  
pp. 139 ◽  
Author(s):  
AM Stewart
Keyword(s):  
Rare Earth ◽  
Crystal Field ◽  
Conduction Electron ◽  
Mean Field ◽  
Exchange Interactions ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Polarization Effects ◽  
Formal Procedure ◽  
The Mean

The formal procedure is demonstrated for calculating the magnetization of a rare earth material, in the mean field approximation, at arbitrary fields and temperatures when account is taken of crystal-field splittings, interionic exchange interactions and conduction electron polarization effects.

Partially Disordered State in the Frustrated Heisenberg Ferrimagnet

2014 ◽  
Vol 215 ◽  
pp. 55-60 ◽  
Author(s):  
Sergey N. Martynov
Keyword(s):  
Phase Diagram ◽  
Phase Transitions ◽  
Magnetic Phase ◽  
Mean Field ◽  
Exchange Interactions ◽  
Field Approximation ◽  
Magnetic Phase Transitions ◽  
Mean Field Approximation ◽  
The Mean ◽  
Competition Parameter

A model for the description of two-subsystem Heisenberg ferrimagnet with frustrated intersubsystem exchange and competition between exchange interactions in a subsystem is proposed. The conditions of the existence of noncollinear Yafet-Kittel state and partially ordered magnetic structure are investigated. The phase diagram of competition parameter vs temperature is obtained in the mean field approximation. The peculiarities of the succesive magnetic phase transitions are considered.

scholarly journals Электронные и магнитные свойства сплавов DyFe-=SUB=-4-=/SUB=-Ge-=SUB=-2-=/SUB=- в области фазового перехода

2020 ◽  
Vol 62 (6) ◽  
pp. 823
Author(s):  
М.В. Матюнина ◽  
М.А. Загребин ◽  
В.В. Соколовский ◽  
В.Д. Бучельников
Keyword(s):  
Magnetic Properties ◽  
Mean Field ◽  
Magnetic Ordering ◽  
Exchange Interactions ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Local Spin Density Approximation ◽  
Electronic And Magnetic Properties ◽  
Strong Localization ◽  
The Mean

Abstract The first-principles studies have been performed for the electronic and magnetic properties of DyFe_4Ge_2 alloys near the P 4_2/ mmm – Cmmm phase transition. The calculations are carried out in a local spin density approximation taking into account the Coulomb interaction within the limit of strong localization in a mean field approximation. The electronic and magnetic properties of the tetragonal structure are shown to be weakly changed in the dependence on the Coulomb and exchange interactions and also on the choice of the approximations. In the case of the orthorhombic structure, a change in the parameters of the Coulomb and exchange interactions leads to a change in the magnetic ordering: from the ferromagnetic to ferrimagnetic in the strong localization limit and from the ferromagnetic to paramagnetic in the mean field approximation.

The Curie Temperature of the Ferroelectric Superlattice Films with Surface Modification

2009 ◽  
Vol 64 (11) ◽  
pp. 723-728
Author(s):  
Bao-Bing Zheng ◽  
Xiao-Yu Kuang ◽  
Shao-Mei Chang ◽  
Ya-Ru Zhao ◽  
Wen-Qiang Li
Keyword(s):  
Surface Modification ◽  
Ising Model ◽  
Mean Field ◽  
Transverse Field ◽  
Exchange Interactions ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Model Parameters ◽  
Transverse Ising Model ◽  
The Mean

We examine the critical behaviour of a finite alternating ferroelectric superlattice based on the transverse Ising model within the framework of the mean-field approximation. The results indicate that the features of the phase diagrams can be greatly modified by changing the transverse Ising model parameters. The transition temperature of alternating superlattice is described as function of the inter- and intra-layer exchange interactions, the strength of the transverse field, the superlattice thickness and the polarizations. In addition, the effects of surface modification on finite superlattices are also studied.

INTERPLAY OF ANTIFERROMAGNETISM AND SUPERCONDUCTIVITY IN RARE EARTH NICKEL BOROCARBIDES

2001 ◽  
Vol 15 (19n20) ◽  
pp. 2519-2533 ◽  
Author(s):  
S. N. BEHERA ◽  
B. N. PANDA ◽  
G. C. ROUT ◽  
P. ENTEL
Keyword(s):  
Rare Earth ◽  
Heavy Fermion ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Qualitative Explanation ◽  
The Mean ◽  
Heavy Fermion Superconductors ◽  
Nickel Borocarbides ◽  
The Rare Earth

A review of some of the anomalous properties observed in rare earth nickel borocarbide superconductors is presented. A model proposed earlier for heavy fermion superconductors is adopted to the rare earth nickel borocarbides. Even though the model is solved in the mean field approximation, it provides qualitative explanation to many of the anomalous experimental observations.

scholarly journals The Combined Effect of Rotation and Magnetic Field on Finite-Amplitude Thermal Convection

1973 ◽  
Vol 26 (5) ◽  
pp. 617 ◽  
Author(s):  
R Van der Borght ◽  
JO Murphy
Keyword(s):  
Magnetic Field ◽  
Mean Field ◽  
Field Approximation ◽  
Finite Amplitude ◽  
Combined Effect ◽  
Mean Field Approximation ◽  
Free Boundaries ◽  
Wide Range ◽  
The Mean ◽  
Basic Equations

The combined effect of an imposed rotation and magnetic field on convective transfer in a horizontal Boussinesq layer of fluid heated from below is studied in the mean field approximation. The basic equations are derived by a variational technique and their solutions are then found over a wide range of conditions, in the case of free boundaries, by numerical and analytic techniques, in particular by asymptotic and perturbation methods. The results obtained by the different techniques are shown to be in excellent agreement. As for the linear theory, the calculations predict that the simultaneous presence' of a magnetic field and rotation may produce conflicting tendencies.

scholarly journals Locating the critical end point using the linear sigma model coupled to quarks.

2018 ◽  
Vol 172 ◽  
pp. 02003
Author(s):  
Alejandro Ayala ◽  
J. A. Flores ◽  
L. A. Hernández ◽  
S. Hernández-Ortiz
Keyword(s):  
Sigma Model ◽  
Chemical Potential ◽  
Potential Temperature ◽  
Mean Field ◽  
Field Approximation ◽  
Baryon Density ◽  
Linear Sigma Model ◽  
Mean Field Approximation ◽  
End Point ◽  
The Mean

We use the linear sigma model coupled to quarks to compute the effective potential beyond the mean field approximation, including the contribution of the ring diagrams at finite temperature and baryon density. We determine the model couplings and use them to study the phase diagram in the baryon chemical potential-temperature plane and to locate the Critical End Point.

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