Micromagnetic analysis of magnetization reversal in CoPt alloy films

Valentin, J.-P.; Kleinefeld, Th.; Weller, D.

doi:10.1088/0022-3727/29/5/001

Cited by 16 publications

(13 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Correspondingly, characteristic differences for the hysteresis loops have been found. Similar results have been achieved by simulations of a micromagnetic model using zero temperature dynamics [3,4] and Monte Carlo methods respectively [5].…”

Section: Introductionsupporting

confidence: 77%

“…1, with the corresponding experimental hysteresis loop for room temperature, see Ref. [3,4]. The qualitative agreement is very good.…”

Section: Hysteresis and The Reversal Mechanismsupporting

confidence: 56%

“…Which of these mechanisms dominates a reversal process depends on the interplay of the different interaction forces between domains with different magnetic orientation. In recent experiments on Co 28 Pt 72 alloy films [3,4] a crossover from magnetisation reversal dominated by domain growth to a reversal dominated by a continuous nucleation of domains was found depending on the film thickness which was varied from 10nm to 30nm. Correspondingly, characteristic differences for the hysteresis loops have been found.…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Domain dynamics of magnetic films with perpendicular anisotropy

Nowak¹,

Heimel²,

Kleinefeld³

et al. 1997

Phys. Rev. B

View full text Add to dashboard Cite

We study the magnetic properties of nanoscale magnetic films with large perpendicular anisotropy comparing polarization microscopy measurements on Co28Pt72 alloy samples based on the magneto-optical Kerr effect with Monte Carlo simulations of a corresponding micromagnetic model. In our model the magnetic film is described in terms of single-domain magnetic grains, interacting via exchange as well as via dipolar forces. Additionally, the model contains an energy barrier which has to be overcome in order to reverse a single cell and a coupling to an external magnetic field. Disorder is taken into account.We focus on the understanding of the dynamics especially the temperature and field dependence of the magnetisation reversal process. The experimental and simulational results for hysteresis, the reversal mechanism, domain configurations during the reversal, and the time dependence of the magnetisation are in very good qualitative agreement. The results for the field and temperature dependence of the domain wall velocity suggest that for thin films the hysteresis can be described as a depinning transition of the domain walls rounded by thermal activation for finite temperatures. 75.60.Ch, 75.60.Ej, 75.40.Mg

show abstract

Section: Introductionsupporting

confidence: 77%

“…1, with the corresponding experimental hysteresis loop for room temperature, see Ref. [3,4]. The qualitative agreement is very good.…”

Section: Hysteresis and The Reversal Mechanismsupporting

confidence: 56%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Domain dynamics of magnetic films with perpendicular anisotropy

Nowak¹,

Heimel²,

Kleinefeld³

et al. 1997

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…10 A square shape for the hysteresis loop is related, for films with a high uniaxial anisotropy, to a magnetization reversal that begins at a few nucleation centers, followed by an expansion of these domains by DW propagation. 11 Since the coercive field is well above the Walker critical field H crit =2␣M s = 256 Oe in our case ͑with a damping parameter ␣ = 0.12͒, 12 DW motion is not thermally activated but viscous, leading to a smooth shape for the DWs. 2,13 Patterning the film leads to an increase in the coercive field, which reaches about the same value for the 0.5 and 0.2 m dots.…”

Section: Resultsmentioning

confidence: 77%

Dynamic magnetization reversal inCoPt3dots: Magnetic force microscopy measurements at remanence

et al. 2008

View full text Add to dashboard Cite

We have studied the magnetization reversal of Co 28 Pt 72 single crystal dots down to 0.2 m diameter with perpendicular anisotropy under slow magnetic field sweep rates ͑10 4 Oe/ s͒ as well as with field pulses ͑6.7 ϫ 10 11 Oe/ s͒. The magnetic state of the dots in the remanent state is observed by magnetic force microscopy. After application of short field pulses, 1 m dots are frequently multidomain, whereas 0.2 m dots are always single domain. The nucleation volume is estimated either from aftereffect measurements or by fitting the increase of the dynamic coercive field versus field sweep rate. Its value amounts to a few 10 −19 cm 3 . We show that the wall velocity around nucleation centers is larger than in the rest of the sample.

show abstract

“…Once a nucleus begins to grow the domain wall motion does not stop until the magnetisation has completely changed. The nucleation field for the simulation is too high compared to the corresponding experimental results [2,3]. There are several possible reasons for this effect.…”

Section: Micromagnetic Modelmentioning

confidence: 86%

Micromagnetic simulation of nanoscale films with perpendicular anisotropy

Nowak¹

1997

Journal of Applied Physics

View full text Add to dashboard Cite

A model is studied for the theoretical description of nanoscale magnetic films with high perpendicular anisotropy. In the model the magnetic film is described in terms of single domain magnetic grains with Ising-like behavior, interacting via exchange as well as via dipolar forces. Additionally, the model contains an energy barrier and a coupling to an external magnetic field. Disorder is taken into account in order to describe realistic domain and domain wall structures. The influence of a finite temperature as well as the dynamics can be modeled by a Monte Carlo simulation.Many of the experimental findings can be investigated and at least partly understood by the model introduced above. For thin films the magnetisation reversal is driven by domain wall motion. The results for the field and temperature dependence of the domain wall velocity suggest that for thin films hysteresis can be described as a depinning transition of the domain walls rounded by thermal activation for finite temperatures. 75.40.Mg,

show abstract

Micromagnetic analysis of magnetization reversal in CoPt alloy films

Cited by 16 publications

References 18 publications

Domain dynamics of magnetic films with perpendicular anisotropy

Domain dynamics of magnetic films with perpendicular anisotropy

Dynamic magnetization reversal inCoPt3dots: Magnetic force microscopy measurements at remanence

Micromagnetic simulation of nanoscale films with perpendicular anisotropy

Contact Info

Product

Resources

About