Use of finite size and applied magnetic field to characterize the interimpurity interaction in a spin glass

1995 ◽  
Vol 51 (2) ◽  
pp. 945-953 ◽  
Author(s):  
K. R. Lane ◽  
M. Park ◽  
M. S. Isaacson ◽  
J. M. Parpia
Keyword(s):  
Magnetic Field ◽  
Spin Glass ◽  
Applied Magnetic Field ◽  
Finite Size

Acoustic susceptibility of an insulating spin-glass in an applied magnetic field

1991 ◽  
Vol 1 (3) ◽  
pp. 415-440 ◽  
Author(s):  
P. Doussineau ◽  
A. Levelut ◽  
W. Schön
Keyword(s):  
Magnetic Field ◽  
Spin Glass ◽  
Applied Magnetic Field

Hysteresis Loop Shifts in Magnetic Field Cooled FeOOH Nanoparticles

1999 ◽  
Vol 581 ◽  
Author(s):  
M.S. Seehra ◽  
Paromita Roy ◽  
A. Manivannan
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loop ◽  
Spin Glass ◽  
Applied Magnetic Field ◽  
Magnetic Moment ◽  
Open Loop ◽  
Zero Field ◽  
Interparticle Interactions

ABSTRACTMeasurements of the magnetization M as a function of temperature (5K - 300K) and applied magnetic field H (up to 50 kOe) in 30 Å particles of FeOOH are reported. M increases with decreasing T, peaking at TB = 65 K below which the ZFC (zero-field-cooled) and the FC (field-cooled) data separate. Hysteresis loop measured at 10 K for ZFC shows an open loop up to 40 kOe with coercivity = 2 kOe. For the FC case, the loop shifts and the loop-shift increases with the cooling field ItL, approaching saturation above Hc = 20 kOe. From the variation of M vs H above TB, a magnetic moment/particle μp = 300 μB is determined. These results suggest that the FeOOH nanoparticles have an antiferromagnetically ordered core with uncompensated surface spins yielding μp and the surface spins order in a spin-glass-like state below TB, possibly due to interparticle interactions.

scholarly journals Ordering In A Spin Glass under Applied Magnetic Field

1999 ◽  
Vol 83 (24) ◽  
pp. 5130-5133 ◽  
Author(s):  
Dorothée Petit ◽  
L. Fruchter ◽  
I. A. Campbell
Keyword(s):  
Magnetic Field ◽  
Spin Glass ◽  
Applied Magnetic Field

scholarly journals Generation of Reverse Meniscus Flow by Applying An Electromagnetic Brake

2021 ◽  
Author(s):  
Alexander Vakhrushev ◽  
Abdellah Kharicha ◽  
Ebrahim Karimi-Sibaki ◽  
Menghuai Wu ◽  
Andreas Ludwig ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Applied Magnetic Field ◽  
Numerical Study ◽  
Flow Direction ◽  
Experimental Studies ◽  
Submerged Entry Nozzle ◽  
Mean Flow ◽  
Slab Caster ◽  
The Mean

AbstractA numerical study is presented that deals with the flow in the mold of a continuous slab caster under the influence of a DC magnetic field (electromagnetic brakes (EMBrs)). The arrangement and geometry investigated here is based on a series of previous experimental studies carried out at the mini-LIMMCAST facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). The magnetic field models a ruler-type EMBr and is installed in the region of the ports of the submerged entry nozzle (SEN). The current article considers magnet field strengths up to 441 mT, corresponding to a Hartmann number of about 600, and takes the electrical conductivity of the solidified shell into account. The numerical model of the turbulent flow under the applied magnetic field is implemented using the open-source CFD package OpenFOAM®. Our numerical results reveal that a growing magnitude of the applied magnetic field may cause a reversal of the flow direction at the meniscus surface, which is related the formation of a “multiroll” flow pattern in the mold. This phenomenon can be explained as a classical magnetohydrodynamics (MHD) effect: (1) the closure of the induced electric current results not primarily in a braking Lorentz force inside the jet but in an acceleration in regions of previously weak velocities, which initiates the formation of an opposite vortex (OV) close to the mean jet; (2) this vortex develops in size at the expense of the main vortex until it reaches the meniscus surface, where it becomes clearly visible. We also show that an acceleration of the meniscus flow must be expected when the applied magnetic field is smaller than a critical value. This acceleration is due to the transfer of kinetic energy from smaller turbulent structures into the mean flow. A further increase in the EMBr intensity leads to the expected damping of the mean flow and, consequently, to a reduction in the size of the upper roll. These investigations show that the Lorentz force cannot be reduced to a simple damping effect; depending on the field strength, its action is found to be topologically complex.

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