Cone phase and magnetization fluctuations in Au/Co/Au thin films near the spin-reorientation transition

Published on Jul 14, 2010in Physical Review B3.575
· DOI :10.1103/PHYSREVB.82.012404
K. A. Seu3
Estimated H-index: 3
(LBNL: Lawrence Berkeley National Laboratory),
Sujoy Roy16
Estimated H-index: 16
(LBNL: Lawrence Berkeley National Laboratory)
+ 3 AuthorsStephen D. Kevan40
Estimated H-index: 40
(UO: University of Oregon)
Using coherent soft x-ray scattering we have measured slow magnetization fluctuations in an Au/Co/Au heterostructure near a thermally driven spin-reorientation phase transition. The intermediate scattering function is well described by a stretched exponential, suggesting cooperative motion through the transition. The decay times were found to exhibit a pronounced maximum as a function of temperature. We argue that the transition proceeds through a cone phase in which the local magnetization evolves continuously from a perpendicular to longitudinal orientation. Our results demonstrate a different and fruitful way to probe the complex spatiotemporal dynamics that arise in unusual magnetic phases with competing anisotropies.
📖 Papers frequently viewed together
6 Citations
4 Citations
Cited By15
#1Sabine Pütter (Forschungszentrum Jülich)H-Index: 4
#1S. Pütter (Forschungszentrum Jülich)H-Index: 2
Abstract The thickness-driven spin-reorientation transition of Co/Au(1 1 1) is studied via in situ Kerr microscopy. On varying the premagnetization conditions in external field of in-plane or normal orientation, the magnetic switching into a final remanent state from an in-plane field is investigated. The quantitative analysis of the Kerr rotation derived from Kerr microscopy images allows the determination of the population of different magnetic phases as a function of thickness. Coexisting mag...
2 CitationsSource
#1Masaki Hada (Okayama University)H-Index: 14
#2Taiki HoshinoH-Index: 10
#1Andrew L. Balk (LANL: Los Alamos National Laboratory)H-Index: 9
#2Fuxiang Li (LANL: Los Alamos National Laboratory)H-Index: 13
Last. Scott A. Crooker (LANL: Los Alamos National Laboratory)H-Index: 54
view all 6 authors...
We use scanning optical magnetometry to study the broadband frequency spectra of spontaneous magnetization fluctuations, or "magnetization noise", in an archetypal ferromagnetic film that can be smoothly tuned through a spin reorientation transition (SRT). The SRT is achieved by laterally varying the magnetic anisotropy across an ultrathin Pt/Co/Pt trilayer, from the perpendicular to in-plane direction, via graded Ar+ irradiation. In regions exhibiting perpendicular anisotropy, the power spectru...
6 CitationsSource
#2K. ColeH-Index: 11
Last. Claudia Mewes (UA: University of Alabama)H-Index: 14
view all 4 authors...
We investigate the influence of lateral variations of the second-order perpendicular anisotropy in thin films on the effective anisotropies required to represent this structure using a macrospin approximation. Second-order and fourth-order effective anisotropies are required for the macrospin approximation. In the case of quasistatic calculations, the fourth-order effective anisotropy is closely linked to deviations of the average magnetization angle from the field direction and lateral variatio...
9 CitationsSource
#1Qu Yang (Ministry of Education)H-Index: 9
#2Xinjun Wang (NU: Northeastern University)H-Index: 15
Last. Ming Liu (Ministry of Education)H-Index: 61
view all 13 authors...
In this work, we synthesized (Co(t)/Pt)3 multilayers and quantitatively determined thickness and temperature dependence of spin reorientation transition (SRT) and perpendicular magnetic anisotropy (PMA) using ferromagnetic resonance measurement. The critical thickness for PMA switching as well as tremendous magnetic anisotropy change up to 645 Oe once the temperature varies from 25 °C to −153 °C are demonstrated. More interestingly, a four-fold symmetry of magnetic anisotropy was found to be pro...
7 CitationsSource
#1Oier Bikondoa (Warw.: University of Warwick)H-Index: 16
Definition of the Topic X-ray photon correlation spectroscopy (XPCS) allows to access a wide variety of dynamic phenomena at the nanoscale by studying the temporal correlations among photons that are scattered by a material when it is illuminated using a coherent X-ray beam. Here, we describe how XPCS is used to study the dynamics of soft and hard condensed matter, review the recent literature and briefly discuss the future of the technique, especially in the context of the emerging diffraction-...
1 CitationsSource
#1Justin M. Shaw (NIST: National Institute of Standards and Technology)H-Index: 38
#2Hans T. Nembach (NIST: National Institute of Standards and Technology)H-Index: 33
Last. Daniel C. Worledge (IBM)H-Index: 28
view all 7 authors...
We used broadband ferromagnetic resonance (FMR) spectroscopy to measure the second- and fourth-order perpendicular magnetic anisotropies in Ta/(t) Co 60 Fe 20 B 20 /MgO layers over a Co 60 Fe 20 B 20 thickness range of 5.0 nm ≥ t ≥ 0.8 nm. Fort > 1.0 nm, the easy axis is in the plane of the film, but when t <; 1.0 nm, the easy axis is directed perpendicular to the surface. However, the presence of a substantial higher order perpendicular anisotropy results in an easy cone state when t = 1.0 nm. ...
45 CitationsSource
#1Joshua J. Turner (SLAC National Accelerator Laboratory)H-Index: 48
#2Georgi L. Dakovski (SLAC National Accelerator Laboratory)H-Index: 25
Last. Michael Holmes (SLAC National Accelerator Laboratory)H-Index: 12
view all 15 authors...
This paper describes the development of new instrumentation at the Linac Coherent Light Source for conducting THz excitation experiments in an ultra high vacuum environment probed by soft X-ray diffraction. This consists of a cantilevered, fully motorized mirror system which can provide 600 kV cm−1 electric field strengths across the sample and an X-ray detector that can span the full Ewald sphere with in-vacuum motion. The scientific applications motivated by this development, the details of th...
13 CitationsSource
#2Gerhard GrübelH-Index: 39
Last. Marlan O. ScullyH-Index: 107
view all 4 authors...
2 Citations
#1Sunil K. Sinha (UCSD: University of California, San Diego)H-Index: 26
#2Zhang Jiang (Argonne National Laboratory)H-Index: 24
Last. Laurence Lurio (NIU: Northern Illinois University)H-Index: 25
view all 3 authors...
The technique of X-ray Photon Correlation Spectroscopy (XPCS) is reviewed as a method for studying the relatively slow dynamics of materials on time scales ranging from microseconds to thousands of seconds and length scales ranging from microns down to nanometers. We focus on the application of this technique to study dynamical fluctuations of surfaces, interfaces and thin films. We first discuss instrumental issues such as the effects of partial coherence (or alternatively finite instrumental r...
54 CitationsSource