scholarly journals Zur spontanen Magnetisierung dünner ferromagnetischer Schichten

1964 ◽  
Vol 19 (13) ◽  
pp. 1580-1591
Author(s):  
Rainer J. Jelitto
Keyword(s):  
Thin Films ◽  
Digital Computer ◽  
Heisenberg Model ◽  
Spontaneous Magnetization ◽  
Preceding Paper ◽  
Cubic Lattice ◽  
Compact Material ◽  
Ferromagnetic Films ◽  
Special Lattice ◽  
The One

In a preceding paper (I) the spectra of the one-spinwave-eigenstates of an ideal HEISENBERG-model for thin ferromagnetic films were derived for a special type of surface-orientations.Now these results are applied to the cubic lattice types. First a theory is given for the calculation of certain coefficients by which the general equations of (I) are related to the special lattice types and surface orientations. It is shown that some of the most important orientations of the cubic lattice types belong to the case treated in (I).For these orientations the dependence of the spontaneous magnetization on temperature and thickness of the film is calculated from the spinwave spectra. The formula obtained for this function was evaluated on a digital computer. The results, some of which are plotted, are discussed and compared with experimental dates.In all cases the deviations from the magnetization of the compact material are found to be small, down to very thin films.

COHERENT-ANOMALY METHOD FOR QUANTUM SPIN SYSTEMS

1988 ◽  
Vol 02 (01) ◽  
pp. 1-11 ◽  
Author(s):  
NOBUYASU ITO ◽  
MASUO SUZUKI
Keyword(s):  
Critical Exponents ◽  
Heisenberg Model ◽  
Spontaneous Magnetization ◽  
Quantum Spin ◽  
Spin Systems ◽  
Quantum Spin Systems ◽  
Cubic Lattice ◽  
Bethe Approximation ◽  
Simple Cubic ◽  
Simple Cubic Lattice

The coherent-anomaly method (CAM) is applied to the Heisenberg model to test the applicability of the CAM for quantum spin systems. The Weiss, Bethe and constant coupling approximations are tried for the Heisenberg model on the simple cubic lattice and estimate the critical exponents of the susceptibility and spontaneous magnetization using the CAM. The results show that the CAM is also powerful for quantum spin systems. The detailed results of the Bethe approximation of the spin-1/2 isotropic Heisenberg model are presented.

Fundamental Research into Thin Films in a Developing Country

1972 ◽  
Vol 30 ◽  
pp. 500-501
Author(s):  
J.A. Eades ◽  
E. Grünbaum
Keyword(s):  
Thin Films ◽  
Growth Process ◽  
Empirical Process ◽  
Nucleation And Growth ◽  
Research Groups ◽  
Film Research ◽  
Fundamental Research ◽  
Controlled Deposition ◽  
The One ◽  
The University

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.

scholarly journals Toeplitz algebras and spectral results for the one-dimensional Heisenberg model

2006 ◽  
Vol 47 (8) ◽  
pp. 082107 ◽  
Author(s):  
Mondher Damak ◽  
Marius Măntoiu ◽  
Rafael Tiedra de Aldecoa
Keyword(s):  
Heisenberg Model ◽  
One Dimensional ◽  
The One

Deposition of Pb(Zr,Ti)O3-Thin Films on Substrates with Shape Memory Effect

1999 ◽  
Vol 596 ◽  
Author(s):  
W. Biegel ◽  
R. Klarmann ◽  
M. Kuhn ◽  
B. Wörz ◽  
B. Stritzker
Keyword(s):  
Thin Films ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Ferroelectric Behavior ◽  
Ceramic Films ◽  
Pzt Films ◽  
The One ◽  
Film Substrate ◽  
La Doped

AbstractPulsed Laser Deposition (PLD) was used to deposit La-doped Pb(Zr,Ti)O3 (PZT) thin films onto NiTi foils. The substrate alloy with composition Ni50Ti50 shows a strong shape memory effect with a transition temperature of about 80°C. This simple bicomponental system could have the potential of an actuator device (NiTi shows a strain up to 5 % during thermal cycling) with an inherent sensorial component (PZT) for the generated elongation. The deposited ceramic films were characterized with respect to their structural properties (XRD) and their ferroelectric behavior (P-E hysteresis). Under certain deposition conditions the growth of pure perovskite PZT on the polycrystalline shape memory alloy was observed. The growth morphology of PZT on NiTi was compared to the one of PZT on single crystalline substrates whereas no distinctive texture of the films on NiTi could be found. The ferroelectric behavior of the PZT films depend on the stage of bending of the film-substrate compound.

CONFINEMENT OF QUARKS AND GLUONS II

1995 ◽  
Vol 10 (22) ◽  
pp. 3155-3167 ◽  
Author(s):  
KAZUHIKO NISHIJIMA
Keyword(s):  
Quantum Chromodynamics ◽  
Preceding Paper ◽  
Asymptotic Freedom ◽  
Color Confinement ◽  
The One

It is shown that color confinement is a consequence of BRS invariance and asymptotic freedom of quantum chromodynamics. BRS invariance is exploited to define color confinement, and asymptotic freedom is utilized to prove it. The proof presented in this paper is an extension of the one in the preceding paper.

Statistics of the simple cubic lattice. II

1951 ◽  
Vol 47 (4) ◽  
pp. 799-810 ◽  
Author(s):  
A. J. Wakefield
Keyword(s):  
Specific Heat ◽  
Curie Point ◽  
Spontaneous Magnetization ◽  
Lattice Structure ◽  
Critical Behaviour ◽  
Cubic Lattice ◽  
Simple Cubic ◽  
Simple Cubic Lattice ◽  
Energy Excess ◽  
Ferromagnetic Substance

Experimentally it is found for a ferromagnetic substance that the spontaneous magnetization decreases as the temperature increases. At a certain temperature called the Curie point, the magnetization disappears (or substantially disappears) and remains zero for higher temperatures. Associated with these magnetic properties is an anomaly in the specific heat. This quantity is greater than that which would be calculated theoretically for the material were it non-magnetic and becomes large when the temperature approaches the Curie point from below. Just above the Curie point there is a sharp but continuous decrease in the specific heat and the system is said to show critical behaviour. We shall examine the Ising model of the ferromagnet with a simple cubic lattice structure, determine the specific heat anomaly and the corresponding energy excess due to magnetism, and also see how the critical behaviour of the model compares with that actually observed.

scholarly journals Non-equilibrium critical behavior of Heisenberg thin films

2018 ◽  
Vol 185 ◽  
pp. 11005
Author(s):  
Maria A. Shlyakhtich ◽  
Pavel V. Prudnikov
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Exponents ◽  
Dynamic Method ◽  
Critical Temperatures ◽  
Time Dynamic ◽  
Ferromagnetic Films ◽  
Time Scaling ◽  
Short Time ◽  
Non Equilibrium

In this work we study the non-equilibrium properties of Heisenberg ferromagnetic films using Monte Carlo simulations by short-time dynamic method. By exploring the short-time scaling dynamics, we have found thickness dependency of critical exponents z, θ′ and β/v for ferromagnetic thin film. For calculating the critical exponents of ferromagnetic films we considered systems with linear size L = 128 and layers number N = 2; 4; 6; 10. Starting from initial configurations, the system was updated with Metropolis algorithm at the critical temperatures

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