Giant magnetoresistance in electrodeposited multilayer films. The influence of superparamagnetic regions

I. Bakonyi, L. Péter, V. Weihnacht, J. Tóth, L. Kiss, C. M. Schneider

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

When preparing an alternating sequence of magnetic (Co or Ni) and non-magnetic (Cu) layers by electrodeposition using the two-pulse plating technique, a dissolution of the less-noble magnetic Co and Ni atoms can take place during the deposition of the more noble and non-magnetic Cu atoms. This process results in changes of the actual sublayer thicknesses with respect to the nominal values and can also cause some chemical intermixing at the magnetic/non-magnetic interfaces. As a consequence, superparamagnetic (SPM) regions with "loose magnetic moments" can form as has been demonstrated for electrodeposited Ni-Cu/Cu multilayers. We have also shown recently for electrodeposited Co-Cu/Cu multilayers that if some fraction of the magnetic layers exhibits SPM behaviour then the observed giant magnetoresistance (GMR) can be quantitatively decomposed into a ferromagnetic (FM) and a SPM contribution. In this paper, the results of a similar GMR decomposition study are presented for two electrodeposited Co-Cu/Cu multilayers. In the multilayer with strongly non-saturated magnetoresistance curves, the dominant GMR term was due to SPM regions, whereas in the other multilayer for which the magnetoresistance is mostly saturated in magnetic fields around 1 to 2 kOe, the FM contribution to the GMR is much larger. At the same time, magnetic measurements on the first multilayer sample have also revealed the presence of a large SPM contribution to the magnetization.

Original languageEnglish
Pages (from-to)589-598
Number of pages10
JournalJournal of Optoelectronics and Advanced Materials
Volume7
Issue number2
Publication statusPublished - Apr 2005

Fingerprint

Giant magnetoresistance
Multilayer films
Multilayers
plating
electrodeposition
magnetic measurement
atoms
dissolving
magnetic moments
Magnetoresistance
decomposition
magnetization
causes
curves
pulses
approximation
magnetic fields
Atoms
Magnetic variables measurement
Magnetic moments

Keywords

  • Electrodeposited multilayers
  • Giant magnetoresistance (GMR)
  • Superparamagnetism (SPM)

ASJC Scopus subject areas

  • Materials Science(all)
  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Physics and Astronomy (miscellaneous)

Cite this

Giant magnetoresistance in electrodeposited multilayer films. The influence of superparamagnetic regions. / Bakonyi, I.; Péter, L.; Weihnacht, V.; Tóth, J.; Kiss, L.; Schneider, C. M.

In: Journal of Optoelectronics and Advanced Materials, Vol. 7, No. 2, 04.2005, p. 589-598.

Research output: Contribution to journalArticle

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