Magnetic domain reversal in ultrathin Co(001) films probed by giant magnetoresistance measurements

Li, S. P.; Samad, A.; Lew, Wen Siang; Xu, Yongbing; Bland, J. A. C.

doi:10.1103/physrevb.61.6871

Cited by 27 publications

(15 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An extra reason for working with Co layers with thickness in the range of 30-50 nm comes from the fact that changes in the magnetic anisotropy of shape origin should be fully effective here; for very thin films (below 30 nm), an in-plane magnetic anisotropy dominates, while for sufficiently thick films (above 50 nm) an out-of-plane magnetic anisotropy is established. [23][24][25] Unfortunately, the requisite of using Co thickness in the range of tens of nanometers meets a strong conflict originating from the morphology of the PE crystals employed here; the as-prepared PMN-PT single crystals have a mean surface roughness in the range of many hundred nanometers as this is evidenced by detailed AFM data (see below). Thus, Co outer layers with thickness of only a few tens of nanometers would probably be ineffective electrodes for voltage delivery since their comparatively small thickness (in respect to the PMN-PT surface roughness) cannot ensure the homogeneous covering of the PMN-PT crystal.…”

Section: Resultsmentioning

confidence: 99%

“…23 Referring to the coercive field H c , we believe that the observed modulation is motivated by two candidate mechanisms: (a) by the pinning of already existing domain walls that can be effectively enhanced either by the surface/interface roughness or "bulk" static disorder that are newly introduced by the developed strain 26-29 and (b) by the modulation of domain walls population that inevitably should accompany the modulation of magnetic domain size due to the deformation of the FM film thickness motivated by the induced strain (the magnetic domain size w is proportional to the square root of the film thickness d, that is w $ d 1/2 ). [23][24][25] Referring to the saturation magnetization m sat , we believe that the observed modulation can be motivated by the change of the magnetic anisotropy due to the change of the shape anisotropy either at the local or global level. For Co it is well known that, except for the magnetocrystalline anisotropy, another mechanism of magnetic anisotropy stems from the dimensional restrictions due to the reduction of the layer thickness (shape anisotropy).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Modulation of the properties of thin ferromagnetic films with an externally applied electric field in ferromagnetic/piezoelectric/ferromagnetic hybrids

Σταμόπουλος

Zeibekis

Zhang

2013

Journal of Applied Physics

View full text Add to dashboard Cite

Modulation of the properties of thin ferromagnetic films with an externally applied electric field in ferromagnetic/piezoelectric/ferromagnetic hybrids AbstractIn many cases, technological advances are based on artificial low-dimensional structures of heterogeneous constituents, thus called hybrids, that when come together they provide stand-alone entities that exhibit entirely different properties. Such hybrids are nowadays intensively studied since they are attractive for both basic research and oncoming practical applications. Here, we studied hybrids constituted of piezoelectric (PE) and ferromagnetic (FM) components in the form FM/PE/FM, ultimately aiming to provide means for the controlled modulation of the properties of the FM electrodes, originating from the strain imposed to them by the PE mediator when an electric field is applied. The PE component is in single crystal form, 0.71Pb(Mg1/ 3Nb 2/3)O3-0.29PbTiO3 (PMN-PT), while the FM outer layers are Cobalt (Co) in thin film form. Detailed magnetization measurements performed under variation of the electric field applied to PMN-PT demonstrated the efficient modulation of the properties of the Co electrodes at low temperature (coercive field modulation up to 27% and saturation magnetization absolute modulation up to 4% at T = 10 K for electric field not exceeding 6 kV/cm). The modulation degree faints upon increase of the temperature, evidencing that the thermal energy eventually dominates all other relevant energy scales. Candidate mechanisms are discussed for the explanation of these experimental observations. The results presented here demonstrate that commercially available materials can result in quantitatively noticeable effects. Thus, such elemental Co/PMN-PT/Co units can be used as a solid basis for the development of devices. 2013 AIP Publishing LLC. In many cases, technological advances are based on artificial low-dimensional structures of heterogeneous constituents, thus called hybrids, that when come together they provide stand-alone entities that exhibit entirely different properties. Such hybrids are nowadays intensively studied since they are attractive for both basic research and oncoming practical applications. Here, we studied hybrids constituted of piezoelectric (PE) and ferromagnetic (FM) components in the form FM/PE/FM, ultimately aiming to provide means for the controlled modulation of the properties of the FM electrodes, originating from the strain imposed to them by the PE mediator when an electric field is applied. The PE component is in single crystal form, 0.71Pb(Mg 1/3 Nb 2/3 )O 3 -0.29PbTiO 3 (PMN-PT), while the FM outer layers are Cobalt (Co) in thin film form. Detailed magnetization measurements performed under variation of the electric field applied to PMN-PT demonstrated the efficient modulation of the properties of the Co electrodes at low temperature (coercive field modulation up to 27% and saturation magnetization absolute modulation up to 4% at T ¼ 10 K for electric field not exceeding 6 kV/cm). The modulation degree fa...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Modulation of the properties of thin ferromagnetic films with an externally applied electric field in ferromagnetic/piezoelectric/ferromagnetic hybrids

Σταμόπουλος

Zeibekis

Zhang

2013

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…In these experiments a TMR signal with rich structure was observed, that was attributed to the details of the underlying magnetization reversal mechanism. Spin-dependent transport measurements have been previously used as an indirect probe of the micromagnetic structure in spin-valves 16 , magnetic tunnel junctions 17 , artificial ferromagnetic layers 18 , and ferromagnetic rings 19 . The basic idea behind these experiments is that the spin-dependent scattering mechanism leads to a resistivity proportional to the (average) relative orientation of the magnetic moments of separated magnetic regions (either nanoparticles or magnetic domains with different magnetization orientation).…”

Section: Introductionmentioning

confidence: 99%

Correlation between tunneling magnetoresistance and magnetization in dipolar-coupled nanoparticle arrays

Kechrakos

Trohidou

2005

Phys. Rev. B

View full text Add to dashboard Cite

The tunneling magnetoresistance (TMR) of a hexagonal array of dipolar coupled anisotropic magnetic nanoparticles is studied using a resistor network model and a realistic micromagnetic configuration obtained by Monte Carlo simulations. Analysis of the field-dependent TMR and the corresponding magnetization curve shows that dipolar interactions suppress the maximum TMR effect, increase or decrease the field-sensitivity depending on the direction of applied field and introduce strong dependence of the TMR on the direction of the applied magnetic field. For off-plane magnetic fields, maximum values in the TMR signal are associated with the critical field for irreversible rotation of the magnetization. This behavior is more pronounced in strongly interacting systems (magnetically soft), while for weakly interacting systems (magnetically hard) the maximum of TMR ( ) occurs below the coercive field ( ), in contrast to the situation for non-interacting nanoparticles () or in-plane fields. The relation of our simulations to recent TMR measurements in self-assembled Co nanoparticle arrays is discussed.

show abstract

“…While many investigations have focused on the orientationdependent magnetization reversal process of ultrathin epitaxial Fe films, such studies in the Cu/Co system have yet received little attention, despite the Cu/Co system having been investigated intensively [8][9][10][11][12][13]. In this work, we investigate the orientation-dependent magnetization reversal in epitaxial FCC Co(0 0 1) films using the effect of the giant magnetoresistance, which method has been widely used to probe the domain reversal processes [14,15].Molecular beam epitaxy techniques were used to grow epitaxial samples in this work. During the growth, in situ reflection high electron diffraction measurements were carried out to confirm epitaxial growth of the FCC-Co films.…”

mentioning

confidence: 98%

Two-jump magnetic switching in ultrathin Co(001) films probed by giant magnetoresistance measurements

Lew

Bland

2006

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

Magnetic domain reversal in ultrathin Co(001) films probed by giant magnetoresistance measurements

Cited by 27 publications

References 14 publications

Modulation of the properties of thin ferromagnetic films with an externally applied electric field in ferromagnetic/piezoelectric/ferromagnetic hybrids

Modulation of the properties of thin ferromagnetic films with an externally applied electric field in ferromagnetic/piezoelectric/ferromagnetic hybrids

Correlation between tunneling magnetoresistance and magnetization in dipolar-coupled nanoparticle arrays

Two-jump magnetic switching in ultrathin Co(001) films probed by giant magnetoresistance measurements

Contact Info

Product

Resources

About