Influence of Magnetic Field on the Unlocking Stress for Dislocation Motion in Cz-Si Depending on Pre-Annealing Time

2005 ◽  
Vol 108-109 ◽  
pp. 163-168
Author(s):  
M. Badylevich ◽  
Vitaly V. Kveder ◽  
Valeri I. Orlov ◽  
Yu. Osipyan

We investigated the effect of magnetic field on the unlocking stress for dislocations in Cz-Si, measured at 600oC, depending on the thermal prehistory of samples. The effect increases with increasing of the duration of sample annealing at 600oC before the magnetic field treatment. The experimental data are consistent with the assumption that the magnetic field stimulate some changes in configuration of oxygen accumulated at dislocations before the magnetic field treatment, but not the state of oxygen in a bulk.

2004 ◽  
Vol 2 (1) ◽  
pp. 188-195
Author(s):  
N. Mihailov ◽  
O. Vankov ◽  
N. Petrova ◽  
D. Kovacheva

AbstractThin films (50–1200 nm) of YFeO3 were deposited on fused silica substrates by spray-pyrolysis using ethylene glycol solution of Y-Fe(III) citric complexes. The films were post deposition annealed at 750°C in static air for 2 h. Films obtained in this way were afterwards irradiated by a burst mode operated Nd-YAG laser (pulse energy 650 mJ, pulse duration 700 μs, energy density 110 mJ/cm2). The laser’s onset was synchronized with that of a magnetic field pulse of nearly square shape (magnetic induction 0.5 T, pulse duration 900 μs). The samples were placed normally to the direction of the magnetic field. The treatment does not affect the phase composition of the film but significantly increases the crystallite sizes of the phases presenting in the sample. The saturation magnetization of the films decreases as a result of the laser and magnetic field treatment and the coercive force increases by 50%.


Geophysics ◽  
1967 ◽  
Vol 32 (4) ◽  
pp. 668-677 ◽  
Author(s):  
Douglas P. O’Brien ◽  
H. F. Morrison

From Maxwell’s equations and Ohm’s law for a horizontally anisotropic medium, it may be shown that two independent plane wave modes propagate perpendicular to the plane of the anisotropy. Boundary conditions at the interfaces in an n‐layered model permit the calculation, through successive matrix multiplications, of the fields at the surface in terms of the fields propagated into the basal infinite half space. Specifying the magnetic field at the surface allows the calculation of the resultant electric fields, and the calculation of the entries of a tensor impedance relationship. These calculations have been programmed for the digital computer and an interpretation of impedances obtained from field measurements may thus be made in terms of the anisotropic layering. In addition, apparent resistivities in orthogonal directions have been calculated for specific models and compared to experimental data. It is apparent that the large scatter of observed resistivities can be caused by small changes in the polarization of the magnetic field.


2006 ◽  
Vol 14 (4) ◽  
Author(s):  
O. Buluy ◽  
Y. Reznikov ◽  
K. Slyusarenko ◽  
M. Nobili ◽  
V. Reshetnyak

AbstractWe describe the experiments on a magnetically-induced drift of the easy axis on a soft surface of photoaligning material fluoro-polyvinyl-cinnamate. We found unexpected partial relaxation of the drift of the easy axis after switching the magnetic field off. This relaxation cannot be explained in a framework of the existing models and requires additional assumptions about the drift process. We propose a model that explains the experimental data suggesting elastic-like behaviour of the polymer fragments during the drift of the easy axis.


2005 ◽  
Vol 20 (2) ◽  
pp. 295-298 ◽  
Author(s):  
G.J. Ma ◽  
C.W. Wu ◽  
W.L. Zhou ◽  
X.L. Guo ◽  
M.F. Ren ◽  
...  

It was found that after treatment under 10T magnetic field and temperature 900 °C the bending strength of NiAl–Cr(Mo)–Hf alloy is increased by about 75%. The fracture section observation shows that the specimens' ductility is enhanced by the magnetic field treatment. Electron probe microanalysis shows that after treatment of the magnetic field the Heusler phases at NiAl/Cr(Mo) grain boundaries are partially dissolved and the small Heusler phases particles at Cr(Mo) and matrix phases interfaces almost dissolved into NiAl matrix.


2016 ◽  
Vol 31 (02) ◽  
pp. 1650005 ◽  
Author(s):  
Roberto Martorelli ◽  
Giovanni Montani ◽  
Nakia Carlevaro

We discuss a stochastic model for the behavior of electrons in a magnetically confined plasma having axial symmetry. The aim of the work is to provide an explanation for the density limit observed in the Frascati Tokamak Upgrade (FTU) machine. The dynamical framework deals with an electron embedded in a stationary and uniform magnetic field and affected by an orthogonal random electric field. The behavior of the average plasma profile is determined by the appropriate Fokker–Planck equation associated to the considered model and the disruptive effects of the stochastic electric field are shown. The comparison between the addressed model and the experimental data allows to fix the relevant spatial scale of such a stochastic field. It is found to be of the order of the Tokamak micro-physics scale, i.e. few millimeters. Moreover, it is clarified how the diffusion process outlines a dependence on the magnetic field as [Formula: see text].


2012 ◽  
Vol 26 (4) ◽  
pp. 375-380 ◽  
Author(s):  
Y. Jamil ◽  
Zia ul Haq ◽  
M. Iqbal ◽  
T. Perveen ◽  
N. Amin

Abstract The magnetic treatment effects on mushroom spawn growth and yield were studied. The spawn of mushroom were exposed to full-wave rectified sinusoidal magnetic field. The spawn were grown after magnetic field treatment under controlled laboratory conditions. The magnetic field treatment resulted in significant increase (P<0.05) in the growth and yield of mushroom. The number of pin heads formed, number of pin heads developed into mature mushrooms, fresh (wet) and dry masses increased up to 38.18, 34.83, 76.43, and 38.26%, respectively, while reduction in number of days for spawn complete running and number of days for appearance of pin heads was found to be -3.14 and -26.86%, respectively.


1998 ◽  
Vol 76 (7) ◽  
pp. 507-513
Author(s):  
O Bolina ◽  
J R Parreira

We show that the ground state of the xy model (ferromagnetic orantiferromagnetic) in a transverse magnetic field h --- for any spin value, in any dimension --- is the state with all spins aligned antiparallel to the field when h is greater than some critical value hc. In particular, for the spin-1/2 linear chain, we study the behavior of correlations as functions of the magnetic field. PACS Nos.: 75.10Jm and 64.60.Cm


2011 ◽  
Vol 335-336 ◽  
pp. 23-27 ◽  
Author(s):  
Chang Ming Li ◽  
Yang Wang ◽  
Xian Wei Yan ◽  
Yan Ming Yang ◽  
Ying Yang ◽  
...  

A static magnetic field is applied during the hot press molding of high-density polyethylene (HDPE)/carbon black (CB)/ferrous powder composites and HDPE/CB/carbon nanotube (CNT) composites. The effect of magnetic field treatment on the temperature-sensing property of polyethylene-based positive temperature coefficient (PTC) composites is investigated. Experimental results indicate that the magnetic field treatment can lead to the alignment of ferrous powders and CNT in HDPE along the direction of the applied external magnetic field, thus guaranteeing the composites have low room-temperature resistivity and high PTC intensity as the concentration of CB is cut down. This also can significantly improve mechanical property and processability of the composites. When the mass concentrations of ferrous powders and CNT are equal, HDPE/CB/ferrous powder composites present better PTC property than HDPE/CB/CNT composites after the magnetic field treatment.


2019 ◽  
Vol 33 (12) ◽  
pp. 1950141
Author(s):  
A. T. Apostolov ◽  
I. N. Apostolova ◽  
J. M. Wesselinowa

The temperature, magnetic field and ion doping dependence of the phonon properties of CuFeO2 are studied on the basis of a microscopic model and using Green’s function technique. The phonon energy decreases with increasing temperature, whereas the phonon damping increases. There is a kink at the phase transition temperature [Formula: see text] which shows the influence of the magnetic field on the phonon properties. The kinks vanish by applying an external magnetic field. By doping of ions with different radius compared to the Fe ion, the phonon energy in CuFeO2 can increase (Ga) or decrease (Sc) with increasing dopant concentration, whereas the damping is always enhanced. The results are compared with those of CuCrO2. Some discrepancies in the literature are discussed. The observed results are in qualitative agreement with the experimental data.


Sign in / Sign up

Export Citation Format

Share Document