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Volume 6

Research & Reviews: Journal of Material Sciences

ISSN: 2321-6212

Magnetic Materials 2018

October 22-23, 2018

Page 58

conference

series

.com

October 22-23, 2018 | Rome, Italy

3

rd

International Conference on

Magnetism and Magnetic Materials

Karine Chesnel, Res. Rev. J Mat. Sci. 2018, Volume 6

DOI: 10.4172/2321-6212-C6-028

Shaping nanoscale magnetic domain memory in exchange-coupled [Co/Pd]IrMn thin films by field

cooling

M

agnetic nanostructures, such as magnetic domains in perpendicular thin ferromagnetic layers, draw an increasing attention

for their potential applications in nanotechnologies. Magnetic domain memory (MDM), i.e. the ability for the domain

pattern to retrieve its exact same spatial configuration through field cycling, can be particularly useful in magnetic recording

technologies. Here, author will show how x-ray synchrotron tools can uniquely probe the behavior of these magnetic systems at

the nanoscale. More particularly, author will review the technique of coherent x-ray magnetic scattering (CXRMS) and how it can

be used to measure MDM in thin ferromagnetic films, as illustrated in Figure 1. Because illuminating a magnetic pattern with

coherent X-rays produces a speckle scattering pattern that is a unique fingerprint of the magnetic domain configuration, cross-

correlating such speckle patterns provides a way tomeasureMDM. Author will present results on [Co/Pd]IrMn exchange bias thin

films that exhibit strong MDM (above 95%) when cooled down below their blocking temperature. By mapping the correlation as

function of magnetic field, author will show how the behavior of MDMdepends onmagnetic history and cooling field. We will see

that, when zero-field cooled, the MDM reaches its maximum value in the coercive region of the magnetization cycle. We will also

see that MDM is fairly robust through field cycling and through heating, all the way up to the blocking temperature. Finally, author

will show howMDM can be fully controlled by adjusting the magnitude of the cooling field: if the film is cooled down under no or

moderate field, MDM stays strong and robust throughout the entire magnetization loop; if the film is cooled with under a strong,

near saturating field, MDM is essentially lost.

Figure 1:

Sketch of the coherent x -ray scattering experiment carried on out ferromagnetic thin films exhibiting domains.

Recent Publications

1. KChesnel et al. (2008)Magneticmemory in ferromagnetic thin films via exchange coupling Physical ReviewB 78:132409.

2. K Chesnel et al. (2011) Oscillating spatial dependence of domain memory in ferromagnetic films mapped via x-ray

speckle correlation. Physical Review B 83:054436.

3. K Chesnel et al. (2013) Field mapping and temperature dependence of magnetic domain memory induced by exchange

couplings. New Journal of Physics 15:023016.

4. KChesnel et al. (2016) Shaping nanoscale magnetic domainmemory in exchange- coupled ferromagnets by field cooling.

Nature Communications 7:11648.

Karine Chesnel

Brigham Young University, USA