Thermomechanical Behaviour of AgNi Multilayers and Magnetoelastic Effects

1993 ◽  
Vol 308 ◽  
Author(s):  
V. Pelosin ◽  
B. Rodmacq ◽  
S.R. Teixeira ◽  
J. Hillairet ◽  
G. Carlotti
Keyword(s):  
Domain Walls ◽  
Defect Density ◽  
Brillouin Scattering ◽  
Magnetic Domain ◽  
Internal Stresses ◽  
State Of Stress ◽  
Thermomechanical Behaviour ◽  
Magnetic Domain Walls ◽  
Vibrating Reed

ABSTRACTThe elastic and anelastic properties of AgNi multilayers prepared by sputtering were investigated during the course of anneal cycles. The respective temperature variations of some of the elastic constants and moduli were followed by Brillouin scattering and dynamical methods based on use of a torsion pendulum and a vibrating-reed system. The last two enabled to investigate the internal damping associated with the presence of two-dimensional defects. It appears that the motion of interfaces and grain boundaries is inhibited by the high defect density. In contrast, substantial effects associated with the motion of the magnetic domain walls were evidenced. Concurrently, internal stresses were studied by in situ deflection measurements. Flow stress values on the order of 1 GPa were observed. Dilatometry experiments showed that a large part of the non-recoverable modifications in the state of stress induced by thermal cycling originates in the densification of the material.

Influence of Heat Treatment on Magnetic and Damping Properties of Fe-11 at.% Al Alloys

2008 ◽  
Vol 137 ◽  
pp. 129-136 ◽  
Author(s):  
Agnieszka Mielczarek ◽  
Werner Riehemann ◽  
Olga A. Sokolova ◽  
Igor S. Golovin
Keyword(s):  
Heat Treatment ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Al Alloys ◽  
Damping Capacity ◽  
Amplitude Dependence ◽  
Magnetic Domain Walls ◽  
Mechanical Damping ◽  
The Difference ◽  
Vibrating Reed

The influence of heat treatment on the amplitude dependence of internal friction in Fe - 11 at. % Al alloys with carbon contents in the range 0.005 - 0.2 at. % has been studied using an inverted torsion pendulum in the temperature range 300 – 950 K and a vibrating reed apparatus at room temperature. The specimens were annealed at 1273 K in vacuum and cooled down with different cooling rates in order to obtain different degrees of order. It was found that ordering is hardly avoidable in Fe - Al alloys with Al contents > 11 at. %. Ordered alloys are characterised by lower damping capacity due to higher coercivity caused by additional pinning of magnetic domain walls by antiphase boundaries. X-ray diffraction investigations indicate that water-cooling suppresses ordering in Fe - 11 at. % Al alloys while cooling in air or in furnace provokes D03–type ordering. Slowly cooled specimens are characterised by higher damping capacity due to lower coercivity than water cooled or plastically deformed specimens. The amplitude dependent magneto-mechanical damping was determined as the difference between amplitude dependent damping without and with saturating magnetic field (~ 20 kA/m). Magneto-mechanical damping was found to be proportional to the strain where the amplitude dependent damping is maximum and reciprocal to the coercivity and saturation polarisation. Cold rolling increases the coercivity and therefore decreases the magneto-mechanical damping. An increase of the grain size in the investigated samples by heat treatment leads to a qualitatively expected decrease of coercivity and therefore to an increase of magneto-mechanical damping.

Magnetic domain wall movement in iron silicon

1993 ◽  
Vol 51 ◽  
pp. 1044-1045
Author(s):  
J.E. Wittig
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Magnetic Domain Wall ◽  
Silicon Alloys ◽  
Iron Silicon ◽  
Domain Wall Movement ◽  
Wall Movement ◽  
Magnetic Domain Walls

Lorentz microscopy in the transmission electron microscope directly images magnetic domains. By changing the magnetic field of the electromagnetic lenses relative to the specimen plane, the movement of the magnetic domain walls and their interaction with microstructural features can be observed in situ. This type of experiment has successfully analyzed the microstructure-domain wall interactions in spinel ferrites and iron-rare-earth-boron magnetic materials. The domain wall motion reveals the qualitative pinning potential of grain boundaries, precipitates, inclusions, stacking faults, and cracks. In addition, these in situ experiments display the dynamics of magnetic domain nucleation. The current study investigates the magnetic domain wall movement in iron silicon alloys. Since magnetic properties such as intrinsic coercivity and permeability are structure sensitive, the influence of microstructure on domain wall movement dictates the soft magnetic behavior.Thin foils of iron-6.5 wt% silicon were prepared by electropolishing ribbons produced by melt spinning techniques. The magnetic domain walls were imaged in the defocused (Fresnel) mode with a Philips CM20T operated at 200 kV.

scholarly journals Phase shifter based on voltage-controlled magnetic domain walls

AIP Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 075225
Author(s):  
Xiao Zhang ◽  
Chen Zhang ◽  
Chonglei Sun ◽  
Xiao Xu ◽  
Liuge Du ◽  
...  
Keyword(s):  
Phase Shifter ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Magnetic Domain Walls

scholarly journals Direct observation of the coherent precession of magnetic domain walls propagating along permalloy nanowires

2006 ◽  
Vol 3 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Masamitsu Hayashi ◽  
Luc Thomas ◽  
Charles Rettner ◽  
Rai Moriya ◽  
Stuart S. P. Parkin
Keyword(s):  
Direct Observation ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Magnetic Domain Walls
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