Magnetic properties of monolayer Co islands on Ir(111) probed by spin-resolved scanning tunneling microscopy

Bickel, Jessica E.; Meier, F.; Brede, Jens; Kubetzka, André; Bergmann, Kirsten; Wiesendanger, R.

doi:10.1103/physrevb.84.054454

Cited by 22 publications

(26 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, we would like to emphasize that the direct consequence of the increased in-plane exchange coupling constant at the chemisorbed sites represents a magnetic hardening effect. This is clearly evidenced by the opening of the hysteresis loop measured experimentally for the graphene/Co/Ir(111) system [9] as compared to the clean Co/Ir(111) substrate [47]. At this point it is important to mention that a similar behavior was observed for the graphene/Fe/Ir(111) system [10,48] and also for an Fe/Ir(111) substrate upon adsorption of coronene molecules and graphene nanoflakes [14].…”

Section: Magneticmentioning

confidence: 54%

Exchange interactions of magnetic surfaces below two-dimensional materials

et al. 2016

View full text Add to dashboard Cite

In this theoretical investigation we demonstrate that the adsorption of spatially extended two-dimensional (2D) π systems such as graphene and hexagonal boron nitride on the ferromagnetic fcc Co(111) surface leads to a specific behavior of the in-plane and interlayer Co-Co magnetic exchange interactions. More specifically, for both systems the magnetic exchange coupling within the first Co layer is enhanced, while the one between the first and the second Co layer is not modified, in contrast to the magnetic interlayer softening induced by organic molecules. Importantly, the in-plane magnetic hardening effect is mainly due to the hybridization between the p z states of the 2D π system and the d states of the Co surface.The ability to prepare high-quality two-dimensional (2D) materials on semiconductor and metal surfaces has opened the path to investigate a variety of fundamental physical properties of such systems, of which graphene [1] is the most prominent example. Among these are the study of a two-dimensional gas of massless Dirac fermions [2], the observation of the quantum Hall effect and Berry phase [3], the prediction of a quantum spin Hall effect [4], and perfect spin filters [5], but also many other interesting physical properties that are reviewed in detail in Refs. [6,7].With the prospect of future spintronics applications, of special interest are the studies of graphene on transitionmetal substrates such as Fe, Co, Ni, and Au that have been the focus of several recent experimental and theoretical investigations [8][9][10][11][12][13][14][15][16]. For instance, the weak hybridization between the graphene π orbitals and the d states of the Au atoms in the case of a graphene-Au-Ni(111) system induces an experimentally measurable Rashba effect into the graphene electronic structure [8,11]. Furthermore, the adsorption of graphene on more reactive substrates such as Co (0001), Co/Ir(111), and Fe/Ir(111) leads to a strong π -d hybridization and consequently to the creation of a new hybrid material whose properties can be considerably different than those of the separated components [9,10,14,17].In this Rapid Communication we explore how the adsorption of spatially extended two-dimensional (2D) π systems such as graphene and hexagonal boron nitride (hBN) on fcc Co(111) modifies the magnetic properties of this substrate. It is important to note that finite-size small π -conjugated systems such as molecules adsorbed on ferromagnetic surfaces can significantly change the magnetic properties of the substrate. For example, experimentally and theoretically it was shown that the deposition of phenalenyl-like molecules on a Co(111) surface reduces the interlayer magnetic exchange coupling between the first and second Co layer, known as interlayer magnetic softening [18,19]. Furthermore, theoretical simulations demonstrated that the paracyclophane molecule chemisorbed on a Fe/W(110) surface locally enhances the magnetic exchange coupling of the metal atoms below the molecule * r.friedrich@fz-juelich.de † n.atodiresei@...

show abstract

Section: Magneticmentioning

confidence: 54%

Exchange interactions of magnetic surfaces below two-dimensional materials

et al. 2016

View full text Add to dashboard Cite

show abstract

“…3c-f): At U = − 0.5 V, Co islands appear bright, when their magnetization direction is aligned parallel to the tip magnetization direction, and dark in the antiparallel case 23 . TbPc 2 molecules adsorbed on the ferromagnetic Co islands show a strong spin-dependent contrast as well: a clear eight-lobe state for an antiparallel and a cross-like appearance for a parallel alignment of tip and sample magnetization directions.…”

Section: Resultsmentioning

confidence: 99%

“…Spin-sensitive probe tips (W tips coated with ~50 monolayers of Fe) and ferromagnetic cobalt nanostructures on an Ir(111) substrate are prepared in vacuo, according to the procedure described in ref. 23.…”

Section: Methodsmentioning

confidence: 99%

Real-space observation of spin-split molecular orbitals of adsorbed single-molecule magnets

Schwöbel¹,

Fu²,

Brede³

et al. 2012

Nat Commun

Self Cite

140

114

View full text Add to dashboard Cite

A key challenge in the field of molecular spintronics, and for the design of single-molecule magnet-based devices in particular, is the understanding and control of the molecular coupling at the electrode interfaces. It was demonstrated for the field of molecular electronics that the characterization of the molecule-metal-interface requires the precise knowledge of the atomic environment as well as the molecular orbitals being involved in electron transport. To extend the field of molecular electronics towards molecular spintronics, it is of utmost importance to resolve the spin character of molecular orbitals interacting with ferromagnetic leads. Here we present first direct real-space images of spin-split molecular orbitals of a single-molecule magnet adsorbed on a ferromagnetic nanostructure. moreover, we are able to determine quantitatively the magnitude of the spin-splitting as well as the charge state of the adsorbed molecule.

show abstract

“…Changes in the magnetization direction of nanostructures. (a) Magnetization curves for a sample of triangular ferromagnetic Co island on Ir(111) (Bickel et al, 2011)) and a paramagnetic Co atom on Pt(111) (Meier et al, 2008); while the percentage of ferromagnetic islands aligned with B as a function of external field yields a hysteresis curve the single atom does not show remanence. (b) Map of differential conductance of a sample of approx.…”

Section: Data Analysis and Initial Interpretationmentioning

confidence: 99%

“…7a). For ferromagnetic samples the hysteresis curve provides important parameters such as remanence, saturation magnetization, and coercive field (Pietzsch et al, 2001;Bickel et al, 2011). From single atom magnetization curves, a fit to theoretical models allows us to determine the magnetic moment (Meier et al, 2008).…”

Section: Data Analysis and Initial Interpretationmentioning

confidence: 99%

Magnetic Sensitive Scanning Tunneling Microscopy

Bergmann¹,

Kubetzka²

2012

Characterization of Materials

Self Cite

View full text Add to dashboard Cite

The scanning tunneling microscope is capable of studying magnetism at surfaces down to the atomic scale. Using spin‐polarized tips even complex magnetic ground states of surfaces and nanostructures can be revealed. The technique of spinpolarized scanning tunneling microscopy can also be applied to study the switching of individual (super)paramagnetic objects as a function of temperature or magnetic field and recently it has been shown that the magnetic state of nanoscale objects can also be manipulated. In addition one can study magnetic excitations by employing spin excitation spectroscopy and thereby deduce the spin, the anisotropy, the type and strength of magnetic coupling and even relaxation times of single atoms or small clusters. Combining these techniques with atom manipulation provides access to fundamental magnetic phenomena on the atomic scale.

show abstract

Magnetic properties of monolayer Co islands on Ir(111) probed by spin-resolved scanning tunneling microscopy

Cited by 22 publications

References 22 publications

Exchange interactions of magnetic surfaces below two-dimensional materials

Exchange interactions of magnetic surfaces below two-dimensional materials

Real-space observation of spin-split molecular orbitals of adsorbed single-molecule magnets

Magnetic Sensitive Scanning Tunneling Microscopy

Contact Info

Product

Resources

About