The influence of sublayer thickness on GMR and magnetisation reversal in permalloy/Cu multilayers

Luciński, T.; Stobiecki, F.; Elefant, D.; Eckert, D.; Reiss, Günter; Szymański, B.; Dubowik, J.; Schmidt, M.; Rohrmann, H.; Roell, K.

doi:10.1016/s0304-8853(97)00217-5

Cited by 40 publications

(24 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…58 Also, the SPM type GMR contribution as discussed above is not unique to electrodeposited multilayers since it was found in several physically deposited multilayers as well. 66,[72][73][74][75][76] V. SUMMARY In order to clarify the controversial results for the spacer layer thickness dependence of GMR in electrodeposited multilayers, a detailed study of the GMR evolution was performed on Co/Cu multilayers prepared under controlled electrochemical conditions with Cu layer thicknesses ranging from 0.5 nm to 4.5 nm. It turned out that for thin Cu layers (up to 1.5 nm) AMR only occurs.…”

Section: Origin Of Gmr In Electrodeposited Co/cu Multilayers and Ementioning

confidence: 99%

Giant magnetoresistance in electrodeposited Co-Cu/Cu multilayers: Origin of the absence of oscillatory behavior

et al. 2009

View full text Add to dashboard Cite

─ A detailed study of the evolution of the magnetoresistance was performed on electrodeposited Co/Cu multilayers with Cu layer thicknesses ranging from 0.5 nm to 4.5 nm. For thin Cu layers (up to 1.5 nm), anisotropic magnetoresistance (AMR) was observed whereas multilayers with thicker Cu layers exhibited clear giant magnetoresistance (GMR) behaviour. The GMR magnitude increased up to about 3.5 to 4 nm Cu layer thickness and slightly decreased afterwards. According to magnetic measurements, all samples exhibited ferromagnetic (FM) behaviour. The relative remanence turned out to be about 0.75 for both AMR and GMR type multilayers. This clearly indicates the absence of an antiferromagnetic (AF) coupling between adjacent magnetic layers for Cu layers even above 1.5 nm where the GMR effect occurs. The AMR behaviour at low spacer thicknesses indicates the presence of strong FM coupling (due to, e.g., pin-holes in the spacer and/or areas of the Cu layer where the layer thickness is very small). With increasing spacer thickness, the pin-hole density reduces and/or the layer thickness uniformity improves which both lead to a weakening of the FM coupling. This improvement in multilayer structure quality results in a better separation of magnetic layers and the weaker coupling (or complete absence of interlayer coupling) enables a more random magnetization orientation of adjacent layers, all this leading to an increase of the GMR. Coercive field and zero-field resistivity measurements as well as the results of a structural study reported earlier on the same multilayers provide independent evidence for the microstructural features established here. A critical analysis of former results on electrodeposited Co/Cu multilayers suggests the absence of an oscillating GMR in these systems. It is pointed out that the large GMR reported previously on such Co/Cu multilayers at Cu layer thicknesses around 1 nm can be attributed to the presence of a fairly large superparamagnetic (SPM) fraction rather than being due to a strong AF coupling. In the absence of SPM regions as in the present study, AMR only occurs at low spacer thicknesses due to the dominating FM coupling.

show abstract

Section: Origin Of Gmr In Electrodeposited Co/cu Multilayers and Ementioning

confidence: 99%

Giant magnetoresistance in electrodeposited Co-Cu/Cu multilayers: Origin of the absence of oscillatory behavior

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The authors of these papers emphasised that the antiferromagnetic (AF) coupling energy as well as GMR of these multilayers strongly depended on the conditions of deposition. In our earlier works on Py/Cu multilayers [3] we have shown that the deposition method of face-to-face sputtering allows much lower values of AF coupling energy than those achieved in multilayers deposited by other techniques. We obtained high sensitivity of GMR, i.e., S 0.6%/Oe.…”

Section: Introductionmentioning

confidence: 89%

Magnetic Properties and GMR of Sputtered Permalloy/Au Multilayers

Szymański

Stobiecki

2000

Acta Phys. Pol. A

View full text Add to dashboard Cite

We report on structural, magnetic, and GMR properties of permalloy/Au multilayers where permalloy = Ni83 Fe17 , deposited by face-to-face sputtering onto Si(111) substrate. X-ray diffraction studies confirmed a good structural quality of our multilayers. The samples were characterised with vibrating sample magnetometer, longitudinal magnetooptical Kerr effect and giant magnetoresistance measurements. It was determined that our multilayers are magnetically very soft with Ηc 1 Oe and show uniaxial anisotropy with Ηι' 5 Oe. For gold sublayer thickness dΑ close to 1.1 nm the antiferromagnetic coupling is present in very narrow Au thickness range ( ≈ 0.2 nm).Despite a good structural quality of samples relatively small giant magnetoresistance value (1.2% at room temperature) was found. It is due to non-perfect aniferromagnetic coupling caused by pinholes.

show abstract

“…The deposition rates were 0.05 nm/s for Py and 0.1 nm/s for Cu sublayers. The Cu sublayer thickness was chosen so as to obtain the samples from the second AF-coupling range [10,11] and the Py sublayer thickness used maximizes the GMR value in the Py/Cu MLs [3,11]. High-angle X-ray diffraction measurements showed that a reference sample with N = 31 was polycrystalline with a weak (111) texture.…”

Section: Methodsmentioning

confidence: 99%

“…4) clearly indicates that the magnetization of the first Py sublayers is smaller than that of the sublayers more distant from the substrate. This is most probably due to intermixing processes leading to the appearance of (Ni-Fe)-Cu alloy at the interfaces [11,18] and may indicate that the thickness of the alloy region is higher at the Py/Cu interfaces which lie close to the substrate than in the rest of the ML. In the near substrate regions a higher density of grain boundaries (Fig.…”

Section: As-deposited Multilayersmentioning

confidence: 99%

Annealing Effects on Py/Cu GMR Multilayer Films with Limited Number of Sublayers

Urbaniak

Stobiecki

Luciński

et al. 2001

phys. stat. sol. (a)

View full text Add to dashboard Cite

The influence of annealing on giant magnetoresistance (GMR) effect and magnetization reversal processes has been investigated in Py/Cu (Py = Ni 83 Fe 17 ) sputter-deposited multilayers (MLs) with a limited number of magnetic sublayers (N 6) and equal sublayer thicknesses both for Py and Cu (t Cu = 2 nm, t Py = 2 nm). Based on the magnetization and magnetoresistance measurements it has been shown that the magnetic behavior of such MLs is strongly influenced by annealing driven disruption of magnetic layers (lateral decoupling) and nonmagnetic layers (magnetic bridging between Py layers). A comparison of experimental hysteresis curves with model dependences indicates that annealing causes a change of the magnetization reversal from a local to an absolute energy minimum mode leading to quasi-two-state magnetoresistance characteristics.

show abstract

The influence of sublayer thickness on GMR and magnetisation reversal in permalloy/Cu multilayers

Cited by 40 publications

References 18 publications

Giant magnetoresistance in electrodeposited Co-Cu/Cu multilayers: Origin of the absence of oscillatory behavior

Giant magnetoresistance in electrodeposited Co-Cu/Cu multilayers: Origin of the absence of oscillatory behavior

Magnetic Properties and GMR of Sputtered Permalloy/Au Multilayers

Annealing Effects on Py/Cu GMR Multilayer Films with Limited Number of Sublayers

Contact Info

Product

Resources

About