BARC/PUB/2015/0720

 
 

Low temperature effect on magnetic conversion and giant magnetoresistance in electrodeposited CoCu/Cu multilayers

 
     
 
Author(s)

Ghosh, S. K.; Dogra, A.; Chowdhury, P.; Rajak, S.; Srivastava, C.
(MPD)

Source

Journal of Alloys & Compounds, 2015. Vol. 647: pp. 1098-1103

ABSTRACT

In the present study, the variation of super paramagnetic (SPM) and ferromagnetic (FM) components and their effect on giant magneto resistance (GMR) in electrodeposited CoCu/Cu multi layers (ML's) were investigated in the temperature range 30e 300 K. For this, two different kinds of ML's, one with discontinuous Co-layer consisting of large super paramagnetic (SPM) (tCo=0.2 and 0.3 nm) fractions and the other with continuous Co-layer containing large ferromagnetic (FM) (tCo=2 and 3 nm) content were considered. Magneto resistance measurements showed increase in MR magnitude with decrease in temperature associated with magnetic conversions in the magnetic Co-layers. At 300 K, a substantial difference in magnitude of MR was found for multi layers with tCo=0.3 (5.07%) and 3 nm (8.82%). However, at 30 K very close values of MR for multilayer pair with tCo=0.3 (16.48%) and 3 nm (17.72%) ensures a significant transformations of SPM to FM fractions in Co-layer at tCo=0.3 nm. Similar results were obtained for the other pair of ML's i.e. tCo=0.2 and 2 nm. This study suggests a suitable minimization of SPM content in the Co-layer could be another effective mechanism in maximizing the MR value. The measured temperature dependence of MR obeyed a simple T1 law.

 
 
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