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

Depinning transition of the quenched Mullins–Herring equation: A short-time dynamic method

2008 ◽  
Vol 372 (47) ◽  
pp. 7077-7080 ◽  
Author(s):  
Huan Liu ◽  
Wei Zhou ◽  
Qing-Miao Nie ◽  
Qing-Hu Chen
Keyword(s):  
Dynamic Method ◽  
Time Dynamic ◽  
Depinning Transition ◽  
Short Time

Design and application of gradient annealing devices for the parallel thermal processing of Fe/Pt multilayers

2005 ◽  
Vol 894 ◽  
Author(s):  
Sigurd Thienhaus ◽  
Robert Hiergeist ◽  
Alan Savan ◽  
Alfred Ludwig
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Processing ◽  
Test System ◽  
First Results ◽  
Different Temperatures ◽  
Short Time ◽  
High Throughput Experiments ◽  
Temperature Time ◽  
Annealing Experiments

AbstractThis paper discusses the design and use of gradient annealing devices. Generally, it is intended to use such devices for the rapid optimization of thin film materials by simultaneous thermal processing at different temperatures. Furthermore, these devices are efficient for short- time annealing experiments. They are used in order to quickly vary the annealing parameters (temperature, time) from sample to sample. Here, nanoscale Fe/Pt multilayer precursor thin films for the fabrication of hard magnetic Fe-Pt thin films are investigated as a test system. First results prove the usefulness of the gradient annealing devices for high-throughput experiments.

CRITICAL SHORT-TIME DYNAMICS IN LATTICE GAUGE THEORY

2006 ◽  
Vol 17 (01) ◽  
pp. 1-13 ◽  
Author(s):  
TSUYOSHI OTOBE ◽  
KEISUKE OKANO
Keyword(s):  
Gauge Theory ◽  
Critical Temperature ◽  
Critical Point ◽  
Critical Exponents ◽  
Lattice Gauge Theory ◽  
Time Relaxation ◽  
Time Dynamics ◽  
Lattice Gauge ◽  
Time Scaling ◽  
Short Time

We investigated a critical short-time relaxation in a lattice gauge theory. A systematic procedure of estimating critical point based on the "short-time scaling" is formulated. It is applied to the (2+1)-dimensional SU(2) lattice gauge theory at finite temperature to deduce its critical point. Finally, we studied the short-time relaxation behavior at the critical temperature starting either from "cold" and "hot" initial configuration, and calculated the dynamic critical exponents θ and z, as well as the static exponents β/ν.

Evaluation of TiO2 Nanotube Thin Films Fabricated by Anodic Oxidation

2013 ◽  
Vol 566 ◽  
pp. 204-208
Author(s):  
Yusuke Okumoto ◽  
Ryo Kawakami ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Anodic Oxidation ◽  
Indium Tin Oxide ◽  
Negative Electrode ◽  
Tube Length ◽  
Dye Sensitized ◽  
Ito Glass ◽  
Inner Diameter ◽  
Short Time

Titanium dioxide nanotubes (TNTs) were grown by anodic oxidation of a titanium thin film deposited on an indium tin oxide (ITO) glass substrate. The TNTs were arranged densely and formed a thin film on the ITO substrate. Anodic oxidation was carried out at 550oC in an electrolyte. The inner diameter and tube length of a grown TNT were approximately 15 nm and 0.5 μm, respectively. Several of the TNT tube openings were closed by lids. These lids could be removed by sputter etching for a short time. The crystal structure was non-crystalline. The power conversion efficiency of a dye sensitized solar cell fabricated using the TNT thin film as a negative electrode is much smaller than that fabricated using conventional TiO2 nanoparticle thin films, at present.

Fabrication of Oriented TiO2-Based Nanotube Array Thin Films

2008 ◽  
Vol 135 ◽  
pp. 19-22
Author(s):  
Yu Peng Guo ◽  
Nam Hee Lee ◽  
Hyo Jin Oh ◽  
Cho Rong Yoon ◽  
Chang Kyu Rhee ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Nanotube Array ◽  
Long Time ◽  
Vertically Aligned ◽  
Short Time

In this study, we have successfully developed the technology to grow the nanotube array thin films from dip-coated titania using hydrothermal method. The nanotube array thin film strongly adhered onto the substrate, was formed in short time reaction at 140°C. Even a self-supporting films, consisted of vertically aligned nanotube in large part, were formed after long time reactions at 140°C with 10 μm in thickness. The most probable formation mechanism of TiO2-based nanotube array thin films is discussed.

scholarly journals SHORT-TIME DYNAMIC EXPONENTS OF AN ISING MODEL WITH COMPETING INTERACTIONS

2003 ◽  
Vol 17 (05n06) ◽  
pp. 209-218 ◽  
Author(s):  
NELSON ALVES ◽  
JOSÉ ROBERTO DRUGOWICH DE FELÍCIO
Keyword(s):  
Ising Model ◽  
Critical Exponents ◽  
Order Parameter ◽  
Nearest Neighbor ◽  
Time Correlation ◽  
Time Behavior ◽  
Two Dimensional ◽  
Competing Interactions ◽  
Time Dynamic ◽  
Short Time

In this work the two-dimensional Ising model with nearest- and next-nearest-neighbor interactions is revisited. We obtain the dynamic critical exponents z and θ from short-time Monte Carlo simulations. The dynamic critical exponent z is obtained from the time behavior of the ratio [Formula: see text], whereas the non-universal exponent θ is estimated from the time correlation of the order parameter <M(0)M(t)> ~ tθ, where M(t) is the order parameter at instant t, d is the dimension of the system and <(⋯)> is the average of the quantity (⋯) over different samples. We also obtain the static critical exponents β and ν by investigating the time behavior of the magnetization.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

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