scholarly journals The Study of the Influence of Matrix, Size, Rotation Angle, and Magnetic Field on the Isothermal Entropy, and the Néel Phase Transition Temperature of Fe2O3 Nanocomposite Thin Films by the Monte-Carlo Simulation Method

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1209
Author(s):  
Dung Nguyen Trong ◽  
Van Cao Long ◽  
Ştefan Ţălu
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Phase Transition ◽  
Monte Carlo ◽  
Rotation Angle ◽  
Magnetic Characteristic ◽  
Simulation Method ◽  
Magnetic Devices ◽  
The Matrix ◽  
Fe2o3 Nanoparticle

In this paper, the study of the influence of the matrix structure (mxm) of thin-film, rotation angle (α), magnetic field (B), and size (D) of Fe2O3 nanoparticle on the magnetic characteristic quantities such as the magnetization oriented z-direction (MzE), z-axis magnetization (Mz), total magnetization (Mtot), and total entropy (Stot) of Fe2O3 nanocomposites by Monte-Carlo (MC) simulation method are studied. The applied MC Metropolis code achieves stability very quickly, so that after 30 Monte Carlo steps (MCs), the change of obtained results is negligible, but for certainty, 84 MCs have been performed. The obtained results show that when the mxm and α increase, the magnetic phase transition appears with a very small increase in temperature Néel (TNtot). When B and D increase, TNtot increases very strongly. The results also show that in Fe2O3 thin films, TNtot is always smaller than with Fe2O3 nano and Fe2O3 bulk. When the nanoparticle size is increased to nearly 12 nm, then TNtot = T = 300 K, and between TNtot and D, there is a linear relationship: TNtot = −440.6 + 83D. This is a very useful result that can be applied in magnetic devices and in biomedical applications.

Monte Carlo Modelling of Phase Transitions in Quasi-One-Dimensional Multiferoic

2016 ◽  
Vol 845 ◽  
pp. 158-161
Author(s):  
S.J. Lamekhov ◽  
Dmitry A. Kuzmin ◽  
Igor V. Bychkov ◽  
I.A. Maltsev ◽  
V.G. Shavrov
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Monte Carlo ◽  
Phase Transitions ◽  
Monte Carlo Method ◽  
External Magnetic Field ◽  
Periodic Potential ◽  
One Dimensional ◽  
Field Modelling ◽  
Energy Components

Behavior of quasi-one-dimensional multiferoic Ca3CoMnO6 in external magnetic field was investigated. Modelling by Monte Carlo method was performed to show influence of external magnetic field on appearance of polarization and temperature of phase transition in electric subsystem. Magnetization, polarization and energy components for magnetic and electric subsystems dependencies were achieved for different values of external magnetic field. Modelling showed that periodic potential in form of Frenkel-Kontorova makes influence on maximal values and temperature of phase transitions for magnetization and polarization.

Domain Analysis and Magnetic Relaxation in Thin Films

1998 ◽  
Vol 09 (06) ◽  
pp. 821-825 ◽  
Author(s):  
Tatiana G. Rappoport ◽  
F. S. de Menezes ◽  
L. C. Sampaio ◽  
M. P. Albuquerque ◽  
F. Mello
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Monte Carlo ◽  
Ising Model ◽  
Monte Carlo Simulations ◽  
Magnetic Relaxation ◽  
Film Plane ◽  
Relative Strength ◽  
Two Dimensional ◽  
Magnetic Domains

We have simulated the magnetic relaxation (M(t)) and the nucleation of magnetic domains in the presence of magnetic field in thin films with anisotropy perpendicular to the film plane. We have used Monte Carlo simulations based on the two-dimensional classical Ising model including the long-range dipole–dipole and Zeeman interactions. Domains nucleated during the magnetic relaxation exhibit very rough interfaces. We analyze the roughness and the M(t) as a function of the relative strength of dipole–dipole and Zeeman terms.

Phase Transition in 2D Anisotropic Ising Model with Next-Nearest Neighbor Interactions in a Magnetic Field

SPIN ◽  
2018 ◽  
Vol 08 (03) ◽  
pp. 1850010
Author(s):  
D. Farsal ◽  
M. Badia ◽  
M. Bennai
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Phase Diagram ◽  
Monte Carlo ◽  
Magnetic Susceptibility ◽  
Critical Temperature ◽  
Ising Model ◽  
Nearest Neighbor ◽  
Two Dimensional ◽  
The Magnetic Field

The critical behavior at the phase transition of the ferromagnetic two-dimensional anisotropic Ising model with next-nearest neighbor (NNN) couplings in the presence of the field is determined using mainly Monte Carlo (MC) method. This method is used to investigate the phase diagram of the model and to verify the existence of a divergence at null temperature which often appears in two-dimensional systems. We analyze also the influence of the report of the NNN interactions [Formula: see text] and the magnetic field [Formula: see text] on the critical temperature of the system, and we show that the critical temperature depends on the magnetic field for positive values of the interaction. Finally, we have investigated other thermodynamical qualities such as the magnetic susceptibility [Formula: see text]. It has been shown that their thermal behavior depends qualitatively and quantitatively on the strength of NNN interactions and the magnetic field.

Surface and size effects on the Ferroelectric Phase Transition and Surface Polarization of Thin Films: Monte Carlo Simulations

1997 ◽  
Vol 493 ◽  
Author(s):  
J. Romero ◽  
L. F. Fonseca
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
First Order ◽  
Surface Polarization ◽  
Ferroelectric Phase Transition Temperature ◽  
Model Hamiltonian

ABSTRACTThe macroscopic polarization of ferroelectric thin films was studied by Monte Carlo simulations using a Transverse Ising Model Hamiltonian with four-spins interactions. The dependence of the ferroelectric phase transition temperature, Tc, on the thickness of the film was obtained resulting in a shifting of Tc towards lower temperatures and a change from first-order to second-order phase transition as the thickness of the film is reduced. Comparison between the surface and internal order was carried out by the calculation of layer-averaged polarizations as a function of the sample temperature and the surface interaction parameters. These comparisons show that increasing disorder at the surface can be reverted by increasing the four-spins surface interactions.

Monte Carlo Modelling of Magnetic and Thermodynamic Features of Rb3CoCl5 and Dy3Al5O12 Magnetic Systems

2020 ◽  
Vol 18 (9) ◽  
pp. 719-724
Author(s):  
A. Hendi ◽  
A. Bamuqaddam ◽  
Shatha A. Aldaghfag ◽  
F. Alkallas ◽  
M. Almoneef ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Magnetic Material ◽  
Monte Carlo ◽  
Magnetic Properties ◽  
Ising Model ◽  
Magnetic Phase ◽  
Pyrochlore Structure ◽  
Earth Metal ◽  
Magnetic Systems

In our simulations, we considered two typical magnetic materials, while the first one includes the 3d-transition metal, such as cobalt which is responsible of the presence of magnetism in pyrochlore structure Rb3CoCl5. The second magnetic material was chosen to have 4f-rare earth metal, namely dysprosium that can induce magnetism in garnet material Dy3Al5O12. A general agreement was found between our results and the previous works. In our calculations, we employed the classical Ising model for the above mentioned realistic materials. We specifically studied the magnetic properties over a range of temperature including the critical temperature and above it. To understand the magnetic phase transition, the effect of magnetic field was involved in the classical Ising model.

Stark and Zeeman effects on the topological phase and transport properties of topological crystalline insulator thin films

2020 ◽  
Vol 22 (21) ◽  
pp. 12129-12139
Author(s):  
Pham Thi Huong ◽  
Chuong V. Nguyen ◽  
Huynh V. Phuc ◽  
Nguyen N. Hieu ◽  
Bui D. Hoi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Thin Films ◽  
Phase Transition ◽  
Electric Field ◽  
Transport Properties ◽  
Group Velocity ◽  
Dirac Fermions ◽  
Topological Phase ◽  
Topological Crystalline Insulator

We applied a perpendicular electric field and an in-plane magnetic field to not only tune the Dirac gap of a SnTe(001) thin film and find the phase transition but also to investigate their effects on the group velocity of both massless and massive surface Dirac fermions.

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