Modification of microstructure and magnetic properties of Fe/Cr multilayers caused by ion irradiation

Kopcewicz, M.; Stobiecki, F.; Jagielski, J.; Szymański, B.; Urbaniak, M.; Luciński, T.

doi:10.1016/j.jmmm.2004.09.061

Cited by 8 publications

(3 citation statements)

References 15 publications

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“…In some cases, roughness was varied by changing parameters like substrate temperature, deposition pressure or layer thickness [28][29][30]. In other cases, GMR modifications were produced by irradiation of the Fe/Cr multilayers with energetic Xe + ions of 500 keV [31,32]. An increase in GMR when increasing the ion dose was observed.…”

Section: Introductionmentioning

confidence: 99%

“…However, doses higher than 1×10 13 ions cm −2 led to a reduction of the GMR as more regions of the samples would become ferromagnetically coupled [31]. The formation of pinholes related to the increase of roughness with increasing ion dose, and alloying at the interface due to ion beam induced mixing, have been reported as mechanisms responsible for the degradation of both the GMR and the AF IEC [32].…”

Section: Introductionmentioning

confidence: 99%

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Enhancement of antiferromagnetic coupling in magnetic multilayers by low energy ion beam substrate nanopatterning

Quirós¹,

Peverini²,

Zárate³

et al. 2009

J. Phys.: Condens. Matter

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Ion beam irradiation has been shown to be an interesting tool for tailoring the magnetic properties of thin films and multilayers. The modified properties include magnetic anisotropy, interlayer exchange coupling, exchange bias, magnetic domain structure and magnetization reversal. In this work, new results are shown concerning the enhancement, by one order of magnitude, of the antiferromagnetic coupling strength in amorphous CoSi/Si multilayers by irradiating Si(100) substrates with 1 keV Ar(+) ions. The ion beam exposure induces an increase of the substrate roughness, from 0.07 to 0.88 nm, which enhances antiferromagnetic coupling in the magnetic multilayers grown on top. One possible mechanism governing this enhancement is discussed, related to the formation of magnetic/non-magnetic regions where dipolar interactions could stabilize the antiferromagnetic alignment. The presence of non-magnetic regions is suggested by the observed trend to superparamagnetism, and is expected since the Curie temperature of the amorphous CoSi alloy used is slightly above but very close to room temperature. Accordingly, small fluctuations in the local composition, leading to an enrichment of Si, would produce non-magnetic regions enabling dipolar interactions to take place. Furthermore, the ion beam induced increase of roughness makes surface diffusion of the atoms arriving at the sample difficult, favoring the formation of local non-magnetic inhomogeneities. Finally, the role of other possible mechanisms to enhance antiferromagnetic coupling is also briefly discussed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Enhancement of antiferromagnetic coupling in magnetic multilayers by low energy ion beam substrate nanopatterning

Quirós¹,

Peverini²,

Zárate³

et al. 2009

J. Phys.: Condens. Matter

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“…6,7 In Fe/Cr multilayers, microstructure and magnetic properties can be modified by ion irradiation. 8 For NiFe/CoFe/Cu/CoFe/IrMn spin valves, on both continuous films and patterned elements, it is observed that Ga + ion irradiation results in dramatic decreases in giant magnetoresistivity (GMR) and exchange-bias field together with an increase in the film resistance. 9,10 Since ion irradiation can modify the microstructure and thus properties of magnetic films, it can be used for maskless patterning of magnetic elements by altering the magnetic properties of given regions instead of removing materials as in conventional patterning such as photolithography and electron-beam lithography.…”

Section: Introductionmentioning

confidence: 99%

Magnetic Patterning of Co/Pt Multilayers by Ga+ Ion Irradiation

Wang

Huang

2008

Journal of Elec Materi

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Patterns separated by approximately 55-nm-wide lines on Co/Pt multilayers have been fabricated using a focused ion beam with a 30-keV Ga + ion source. The ion irradiation allows the magnetic moment in the irradiated lines to rotate 45 deg to 90 deg toward the film plane. The in-plane magnetization component of the irradiated lines increases as the ion dose increases. The balance of incoming and outgoing flux at intersections is maintained in orthogonal patterns, while exceptions have been observed in hexagonal and triangular patterns. In all patterns, irradiated lines and adjacent unirradiated elements have no magnetic interaction.

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