Annealing of CoxCu1-x / Cu Multilayers

ABSTRACTIn the multilayer system cobalt / copper at the second antiferromagnetic coupling maximum (2. AFM) with a copper thickness of dCu = 2,2 nm it is possible to reduce magnetoresistive hysteresis by the use of either very thin Co-layers or by alloyed magnetic layers Co1-xCux. It was possible to achieve values for the giant magnetoresistance effect of GMR ≈ 20 % for as prepared samples. A heat treatment was applied to study the degeneration of the system. For annealing at moderate temperatures (Tanneal ≤ 250°C) an increase up to GMR ≈ 25 % was observed. Annealing at slightly higher temperatures lead to an rapid decrease in the GMR effect. To study the structural changes the method of x-ray reflectivity was utilized showing changes in interface roughness as well as in bilayer thickness.

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Giant Magnetoresistance in Annealed Fe/Cr Multilayers

MRS Proceedings ◽

10.1557/proc-313-197 ◽

1993 ◽

Vol 313 ◽

Cited By ~ 5

Author(s):

Noa More Rensing ◽

Bruce M. Clemens

Keyword(s):

Giant Magnetoresistance ◽

Structural Effect ◽

Magnetic Effect ◽

Antiferromagnetic Coupling ◽

X Ray Diffraction ◽

Magnetoresistance Effect ◽

X Ray ◽

Giant Magnetoresistance Effect ◽

Higher Temperature ◽

Spin Dependent Scattering

ABSTRACTThe giant magnetoresistance effect in antiferromagnetically coupled Fe/Cr Multilayers has been attributed to spin dependent scattering at the interfaces between the constituents. One possible source of this spin dependent scattering is chromium impurities in the iron layers due to intermixing at the interfaces. Annealing the films can promote the diffusion of the components, increasing the impurity concentration and therefore the Magnetoresistance. For this study Fe/Cr Multilayers were annealed at several temperatures and for several durations. Annealing at moderate temperatures (∼ 350°C) increases the Magnetoresistance, while higher temperature anneals (∼ 600°C) cause the magnetoresistance to disappear completely. Long anneals at 330°C (> 100 hours) also reduce the Magnetoresistance. VSM Measurements indicate that the antiferromagnetic coupling is reduced in the annealed samples but show no evidence of Magnetically “dead” alloy layers. Low angle X-ray diffraction indicates that the structural effect of annealing is very subtle in comparison to the significant magnetic effect.

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Photoresist-buffer-enhanced antiferromagnetic coupling and the giant magnetoresistance effect of Co/Cu multilayers

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/20/45/452202 ◽

2008 ◽

Vol 20 (45) ◽

pp. 452202 ◽

Cited By ~ 1

Author(s):

Yuan-fu Chen ◽

Yongfeng Mei ◽

Angelo Malachias ◽

Jens Ingolf Mönch ◽

Rainer Kaltofen ◽

...

Keyword(s):

Giant Magnetoresistance ◽

Antiferromagnetic Coupling ◽

Magnetoresistance Effect ◽

Giant Magnetoresistance Effect

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Exchange Coupling and Giant Magnetoresistance in Electrodeposited Co/Cu Multilayers

MRS Proceedings ◽

10.1557/proc-475-611 ◽

1997 ◽

Vol 475 ◽

Cited By ~ 5

Author(s):

A. Dinia ◽

K. Rahmouni ◽

G. Schmerber ◽

H. El Fanity ◽

M. Bouanani ◽

...

Keyword(s):

Exchange Coupling ◽

Giant Magnetoresistance ◽

Room Temperature ◽

X Ray Diffraction ◽

Magnetoresistance Effect ◽

X Ray ◽

Resistivity Measurements ◽

Fee Structure ◽

Giant Magnetoresistance Effect ◽

Spacer Layer

ABSTRACTWe present the results of the transport and magnetization measurements of electrodeposited Co/Cu multilayers grown in a single electrolyte based on C0SO4, H3BO3 and CuSO4. The samples are deposited on glass substrate covered by a 500 Å thick Cu buffer layer. X-ray diffraction performed on the samples shows fee structure of both Co and Cu layers with preferential (111) orientation. Resistivity measurements show a giant magnetoresistance effect of about 4% at room temperature for multilayers with Co and Cu thickness between 4 nm ≤ tco ≤ 6 nm and 3 nm ≤ tcu ≤4 nm respectively. For Co thickness tCo ≤ 15 nm, the magnetoresistance completely vanishes indicating that there is no more continuous Co layer. The indirect antiferromagnetic exchange coupling between magnetic Co layers is relatively large for 4 nm thick Cu spacer layer and gives rise to a temperature dependence of about 30% between room temperature and 4.2 K.

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