Quantitative Fresnel Lorentz microscopy and the transport of intensity equation

McVitie, S.; Cushley, M.

doi:10.1016/j.ultramic.2005.12.001

Cited by 66 publications

(61 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aberration-corrected LTEM imaging combined with electron wave phase retrieval provides a high spatial resolution as well as the ability to obtain quantitative magnetic information at a length scale of nanometers, an order of magnitude smaller than what was the norm thus far in uncorrected LTEM 19 . The phase shift of the electrons in the TEM can be retrieved from a through-focus series of Lorentz images using the paraxial Transport-of-Intensity approach 20 .…”

Section: Experimental Methodsmentioning

confidence: 97%

Nanoscale structure of the magnetic induction at monopole defects in artificial spin-ice lattices

et al. 2011

View full text Add to dashboard Cite

Artificially frustrated spin-ice systems are of considerable interest since they simulate the spin frustration and concomitant rich behavior exhibited by atoms on a crystal lattice in naturally occurring spin-ice systems such as pyrochlores. As a result of the magnetic frustration these systems can exhibit "magnetic monopole" type defects, which are an example of an exotic emergent quasiparticle. The local magnetization structure of such monopole defects determines their stability and thus is critical to understanding their behavior. In this contribution, we report on the direct observation at room temperature of the nano-scale magnetic structure of individual magnetic monopoles in an artificially frustrated two-dimensional square spin-ice lattice, using high resolution aberrationcorrected Lorentz transmission electron microscopy. By combining the high-resolution microscopy with micromagnetic simulation, we demonstrate how nucleation of defect strings, reminiscent of Dirac strings, connecting monopole defects controls the demagnetization process in these spin-ice lattices.

show abstract

Section: Experimental Methodsmentioning

confidence: 97%

Nanoscale structure of the magnetic induction at monopole defects in artificial spin-ice lattices

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The full-width half-maximum (FWHM) of the image intensity perpendicular to divergent 90° domain walls was measured as a function of the defocus distance. The width of the domain wall is estimated by extrapolating the measured FWHM results to zero defocus2425.…”

Section: Methodsmentioning

confidence: 99%

The antiferromagnetic structures of IrMn3 and their influence on exchange-bias

Köhn

Kovács

Fan

et al. 2013

Sci Rep

115

111

View full text Add to dashboard Cite

We have determined the magnetic structures of single-crystal thin-films of IrMn3 for the crystallographic phases of chemically-ordered L12, and for chemically-disordered face-centred-cubic, which is the phase typically chosen for information-storage devices. For the chemically-ordered L12 thin-film, we find the same triangular magnetic structure as reported for the bulk material. We determine the magnetic structure of the chemically-disordered face-centred-cubic alloy for the first time, which differs from theoretical predictions, with magnetic moments tilted away from the crystal diagonals towards the face-planes. We study the influence of these two antiferromagnetic structures on the exchange-bias properties of an epitaxial body-centred-cubic Fe layer showing that magnetization reversal mechanism and bias-field in the ferromagnetic layer is altered significantly. We report a change of reversal mechanism from in-plane nucleation of 90° domain-walls when coupled to the newly reported cubic structure towards a rotational process, including an out-of-plane magnetization component when coupled to the L12 triangular structure.

show abstract

“…It should be noted that, due to small thickness of these films, and hence weak magnetic signal, large defocus values were necessary. Large defocus values can artificially increase the apparent skyrmion size due to delocalization effects 29 . However, for the experimental conditions used here, this effect is expected to be minimal 40,41 .…”

Section: Imaging Néel Skyrmions With L-temmentioning

confidence: 99%

Observation of stable Néel skyrmions in cobalt/palladium multilayers with Lorentz transmission electron microscopy

et al. 2017

View full text Add to dashboard Cite

Néel skyrmions are of high interest due to their potential applications in a variety of spintronic devices, currently accessible in ultrathin heavy metal/ferromagnetic bilayers and multilayers with a strong Dzyaloshinskii–Moriya interaction. Here we report on the direct imaging of chiral spin structures including skyrmions in an exchange-coupled cobalt/palladium multilayer at room temperature with Lorentz transmission electron microscopy, a high-resolution technique previously suggested to exhibit no Néel skyrmion contrast. Phase retrieval methods allow us to map the internal spin structure of the skyrmion core, identifying a 25 nm central region of uniform magnetization followed by a larger region characterized by rotation from in- to out-of-plane. The formation and resolution of the internal spin structure of room temperature skyrmions without a stabilizing out-of-plane field in thick magnetic multilayers opens up a new set of tools and materials to study the physics and device applications associated with chiral ordering and skyrmions.

show abstract

Quantitative Fresnel Lorentz microscopy and the transport of intensity equation

Cited by 66 publications

References 19 publications

Nanoscale structure of the magnetic induction at monopole defects in artificial spin-ice lattices

Nanoscale structure of the magnetic induction at monopole defects in artificial spin-ice lattices

The antiferromagnetic structures of IrMn3 and their influence on exchange-bias

Observation of stable Néel skyrmions in cobalt/palladium multilayers with Lorentz transmission electron microscopy

Contact Info

Product

Resources

About