Statistical and Multifractal Properties of Barkhausen Jumps in Exchange-Coupled Antiferromagnetic/Ferromagnetic Bilayers

2014 ◽  
Vol 215 ◽  
pp. 35-40 ◽  
Author(s):  
Ivan V. Shashkov ◽  
Mikhail A. Lebyodkin ◽  
Vladimir S. Gornakov
Keyword(s):  
Statistical Analysis ◽  
Hysteresis Loop ◽  
Multifractal Analysis ◽  
Material Structure ◽  
Statistical Distributions ◽  
Magnetization Process ◽  
Pinning Centers ◽  
Jump Size ◽  
Optical Indicator ◽  
Indicator Film

Statistical and multifractal properties of Barkhausen jumps in exchange-coupled ferromagnet/antiferromagnet bilayers are studied on Co/IrMn and NiFe/NiO heterostructures using a magneto-optical indicator film technique. The statistical analysis proves a nonstochastic character of magnetization jumps. In particular, power-law behavior is observed for Co/IrMn samples. Furthermore, the statistics depends on the ferromagnet layer thickness and antiferromagnet layer material structure. The average jump size displays an asymmetry between the forward and backward branches of the hysteresis loop, particularly pronounced for the structure with a thin Co layer. In spite of the observation of such an asymmetry in the activity of the domain nucleation and pinning centers, the statistical distributions of jumps do not show any significant differences for two branches of the hysteresis loop. The conclusion on a nonrandom character of the magnetization process is supported by the multifractal analysis which reveals the presence of correlations in the time arrangement of the Barkhausen jumps.

MAGNETIC HYSTERESIS OF HIGH-TEMPERATURE YBa2Cu3Ox-AgO SUPERCONDUCTORS: EXPLANATION OF MAGNETIC SUSPENSION

1988 ◽  
Vol 02 (07) ◽  
pp. 869-874 ◽  
Author(s):  
C.Y. HUANG ◽  
Y. SHAPIRA ◽  
E.J. MCNIFF ◽  
P.N. PETERS ◽  
B.B. SCHWARTZ ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Simple Model ◽  
Hysteresis Loop ◽  
Applied Magnetic Field ◽  
Magnetic Hysteresis ◽  
Magnetic Suspension ◽  
Pinning Centers ◽  
Strong Pinning

We have measured the magnetization M of superconducting YBa 2 Cu 3 O x- AgO composites with T c approximately equal to 92K as a function of an applied magnetic field H at 77 and 87K. A very pronounced M-H hysteresis loop occurs even at 87K, indicating the presence of extremely strong pinning centers. The results of these measurements, together with a simple model, explain quantitatively why these superconductors could be suspended below a magnet.

Magneto-optical indicator film study of the magnetization of a symmetric spin valve

1996 ◽  
Vol 32 (5) ◽  
pp. 4639-4641 ◽  
Author(s):  
V.I. Nikitenko ◽  
V.S. Gornakov ◽  
L.M. Dedukh ◽  
Yu.P. Kabanov ◽  
A.F. Khapikov ◽  
...  
Keyword(s):  
Spin Valve ◽  
Film Study ◽  
Optical Indicator ◽  
Indicator Film

scholarly journals Закономерности статистического распределения механических свойств волокон полиамида-6

2019 ◽  
Vol 45 (14) ◽  
pp. 20
Author(s):  
Ю.М. Бойко ◽  
В.А. Марихин ◽  
О.А. Москалюк ◽  
Л.П. Мясникова ◽  
Е.С. Цобкалло
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Statistical Analysis ◽  
Weibull Distribution ◽  
Young’S Modulus ◽  
Gaussian Distribution ◽  
Young's Modulus ◽  
Polyamide 6 ◽  
Statistical Distributions ◽  
Weibull Distribution Function

A statistical analysis of the distributions of Young's modulus Е and strain at break b of the commercial oriented fibers of polyamide-6 has been carried out in the frameworks of the models of Gauss and Weibull. The duality of the statistical distributions of Е and b revealed earlier for the strength of polyamide-6 has been confirmed. It consists in the validity of the description of the experimental data by using both the normal Gaussian distribution and the standard Weibull distribution function.

scholarly journals The Statistical Analysis of Anisotropy Fluctuations of CMB Temperature in Angular Spatial and Temporal Areas

2021 ◽  
Vol 2081 (1) ◽  
pp. 012035
Author(s):  
V Vargashkin
Keyword(s):  
Statistical Analysis ◽  
Statistical Distributions ◽  
Satellite Measurements ◽  
Data Accumulation ◽  
Cmb Temperature

Abstract The changes in the nature of the statistical distributions of the anisotropy of the temperature of CMB in the satellite measurements of the “WMAP” probe were analyzed for the presence of laws in them in changes within the adjacent periods of data accumulation. Statistical distributions of changes in anisotropy between adjacent data accumulation periods were analyzed. The probability of the occurrence of such unidirectional changes at different frequencies of satellite measurements was analyzed and the probability of their occurrence under the influence of non-random factors was estimated.

scholarly journals Data-driven monitoring of the gearbox using multifractal analysis and machine learning methods

2019 ◽  
Vol 252 ◽  
pp. 06006
Author(s):  
Andrzej Puchalski ◽  
Iwona Komorska
Keyword(s):  
Machine Learning ◽  
Time Series ◽  
Statistical Analysis ◽  
Multifractal Analysis ◽  
Diagnostic Methods ◽  
Data Driven ◽  
Support Vector ◽  
Learning Methods ◽  
Machine Learning Methods ◽  
Wavelet Leaders

Data-driven diagnostic methods allow to obtain a statistical model of time series and to identify deviations of recorded data from the pattern of the monitored system. Statistical analysis of time series of mechanical vibrations creates a new quality in the monitoring of rotating machines. Most real vibration signals exhibit nonlinear properties well described by scaling exponents. Multifractal analysis, which relies mainly on assessing local singularity exponents, has become a popular tool for statistical analysis of empirical data. There are many methods to study time series in terms of their fractality. Comparing computational complexity, a wavelet leaders algorithm was chosen. Using Wavelet Leaders Multifractal Formalism, multifractal parameters were estimated, taking them as diagnostic features in the pattern recognition procedure, using machine learning methods. The classification was performed using neural network, k-nearest neighbours’ algorithm and support vector machine. The article presents the results of vibration acceleration tests in a demonstration transmission system that allows simulations of assembly errors and teeth wear.

scholarly journals Statistical Analysis of Observations of a Complete Sample of Compact Extragalactic Radio Sources

1996 ◽  
Vol 175 ◽  
pp. 97-98
Author(s):  
Y.Y. Kovalev
Keyword(s):  
Statistical Analysis ◽  
Radio Sources ◽  
Statistical Distributions ◽  
Turnover Frequency ◽  
Complete Sample ◽  
Extragalactic Radio Sources ◽  
Bl Lacs

Here are analyzed the results of instantaneous multifrequency observations for a complete sample of 113 extragalactic radio sources (see the paper by Yu.A. Kovalev et al. in these Proceedings) with declinations −30° ÷ 43° from the VLBI–survey. It is tested the hypothesis that quasars and BL Lacs have different nature. Statistical distributions for the turnover flux, turnover frequency, spectral indexes, and other parameters are analyzed.

scholarly journals Inhomogeneous field calibration of a magneto-optical indicator film device

2020 ◽  
Vol 31 (7) ◽  
pp. 075009
Author(s):  
Manuela Gerken ◽  
Sibylle Sievers ◽  
Hans Werner Schumacher
Keyword(s):  
Inhomogeneous Field ◽  
Field Calibration ◽  
Optical Indicator ◽  
Indicator Film
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