Search results for "anisotropy"
showing 10 items of 912 documents
Hierarchies of length-scale based typology in anisotropic U(1)s -wave multiband superconductors
2019
Since Ginzburg and Landau's seminal work in 1950, superconducting states have been classified by the hierarchy of the fundamental length scales of the theory, the magnetic-field penetration lengths ...
Very large magnetoresistance inFe0.28TaS2single crystals
2015
There is great interest in understanding the physics of magnetic ordering and electronic transport in materials of reduced dimensionality with strong spin-orbit coupling. This paper presents magnetotransport measurements of Fe${}_{0.28}$TaS${}_{2}$ single crystals, which are found to exhibit very large magnetoresistance (MR) for magnetic fields along the easy axis. The authors believe that such a large MR arises from spin disorder scattering and propose to use this mechanism as a design principle for materials with large MR. Further tests are needed to fully rule out contributions from a more conventional anisotropic MR mechanism.
Gd-based single-ion magnets with tunable magnetic anisotropy: Molecular design of spin qubits
2012
et al.
Spin-order dependent anomalous Hall effect and magneto-optical effect in the noncollinear antiferromagnets Mn3XN with X=Ga , Zn, Ag, or Ni
2019
The anomalous Hall effect (AHE) and the magneto-optical effect (MOE) are two prominent manifestations of time-reversal symmetry breaking in magnetic materials. Noncollinear antiferromagnets (AFMs) have recently attracted a lot of attention owing to the potential emergence of exotic spin orders on geometrically frustrated lattices, which can be characterized by corresponding spin chiralities. By performing first-principles density functional calculations together with group-theory analysis and tight-binding modeling, here we systematically study the spin-order dependent AHE and MOE in representative noncollinear AFMs ${\mathrm{Mn}}_{3}X\mathrm{N}\phantom{\rule{4pt}{0ex}}(X=\mathrm{Ga}$, Zn, …
Double Exchange in Orbitally Degenerate Mixed Valence Clusters: Magnetic Anisotropy, Vibronic Effects
2001
In this paper we consider the vibronic problem of the double exchange in mixed-valence dimers containing transition metal ions in orbitally degenerate ground states. The vibronic model includes interaction with the breathing local modes (Piepho-Krausz-Schatz-PKS) as well as the modulation of metal-metal distances as suggested by Piepho. The double exchange in orbitally degenerate systems is shown to produce strong magnetic anisotropy of orbital nature. PKS interaction is expected to suppress the magnetic anisotropy of the system, while the intercenter vibrations tend to enhance it. The roles of spin-orbit coupling and temperature are revealed for the systems with different geometries.
Accurate calculation of the transverse anisotropy of a magnetic domain wall in perpendicularly magnetized multilayers
2015
Bloch domain walls are the most common type of transition between two out-of-plane magnetized domains (one magnetized upwards, one downwards) in films with perpendicular magnetic anisotropy. The rotation of the spins of such domain walls in the plane of the film requires energy, which is described by an effective anisotropy, the so-called transverse or hard axis anisotropy ${K}_{\ensuremath{\perp}}$. This anisotropy and the related D\"oring mass density of the domain wall are key parameters of the one-dimensional model to describe the motion of magnetic domain walls. In particular, the critical field strength or current density where oscillatory domain wall motion sets in (Walker breakdown)…
Nuclear orientation of radon isotopes by spin exchange optical pumping
1988
This paper reports the first demonstration of nuclear orientation of radon atoms. The method employed was spin exchange with potassium atoms polarized by optical pumping. The radon isotopes were produced at the ISOLDE isotope separator of CERN. The nuclear alignment of /sup 209/Rn and /sup 223/Rn has been measured by observation of ..gamma..-ray anisotropies and the magnetic dipole moment for /sup 209/Rn has been measured by the nuclear-magnetic-resonance method to be chemically bond..mu..chemically bond = 0.838 81(39)..mu../sub N/.
Experimental determination of single molecule toroic behaviour in a Dy8 single molecule magnet
2019
The enhancement of toroic motifs through coupling toroidal moments within molecular nanomagnets is a new, interesting and relevant approach for both fundamental research and potential quantum computation applications. We investigate a Dy8 molecular cluster and discover it has a antiferrotoroic ground state with slow magnetic relaxation. The experimental characterization of the magnetic anisotropy axes of each magnetic center and their exchange interactions represents a considerable challenge due to the non-magnetic nature of the toroidal motif. To overcome this and obtain access to the low energy states of Dy8 we establish a multi-orientation single-crystal micro Hall sensor magnetometry ap…
Anisotropy in strain gradient elasticity: Simplified models with different forms of internal length and moduli tensors
2018
Abstract Anisotropy of centro-symmetric (first) strain gradient elastic materials is addressed and the role there played by the dual gradient directions (i.e. directions of strain gradient and of double stress lever arm) is investigated. Anisotropy manifests itself not only through the classical fourth-rank elasticity tensor C (21 independent constants) in the form of moduli anisotropy, but also through a sixth-rank elasticity tensor B (171 independent constants) in a unified non-separable form as compound internal length/moduli anisotropy. Depending on the microstructure properties, compound anisotropy may also manifest itself in a twofold separable form through a decoupled tensor B = L C …
Publisher Correction: Stabilizing spin spirals and isolated skyrmions at low magnetic field exploiting vanishing magnetic anisotropy
2018
Skyrmions are topologically protected non-collinear magnetic structures. Their stability is ideally suited to carry information in, e.g., racetrack memories. The success of such a memory critically depends on the ability to stabilize and manipulate skyrmions at low magnetic fields. The non-collinear Dzyaloshinskii-Moriya interaction originating from spin-orbit coupling drives skyrmion formation. It competes with Heisenberg exchange and magnetic anisotropy favoring collinear states. Isolated skyrmions in ultra-thin films so far required magnetic fields as high as several Tesla. Here, we show that isolated skyrmions in a monolayer of Co/Ru(0001) can be stabilized down to vanishing fields. Eve…