Search results for "MAGNETIC ANISOTROPY"

Magnetic states in low-pinning high-anisotropy material nanostructures suitable for dynamic imaging

2013

We present magnetic domain states in a material configuration with high (perpendicular) magnetic anisotropy and particularly low magnetic pinning. This material, a B-doped Co/Pt multilayer configuration, exhibits a strong magnetic contrast in x-ray transmission experiments, making it apt for dynamic imaging with modern synchrotron techniques, providing high spatial and high temporal resolution simultaneously. By analyzing the static spin structures in nanodisks at variable external fields, we show that CoB/Pt multilayers exhibit low enough domain wall pinning to manipulate the domain pattern with weak stimuli and in particular to move domains and domain walls. We demonstrate in a proof-of-p…

Reorientation of magnetization states in Fe-nanostripe arrays on stepped W(110) caused by adsorption of CO, H2 and O2

1999

Abstract Fe-Nanostripe arrays of alternating double layer (DL) and monolayer (ML) stripes were grown on stepped W(1 1 0) surfaces by MBE. Magnetic properties were measured in situ in UHV using the polar and longitudinal magneto-optical Kerr effect (MOKE) during exposure to CO, H2 and O2. The longitudinal Kerr signal increases and the polar signal decreases with increasing exposure of all three gases. A sudden onset of perpendicular remanence was observed at exposures characteristic for each particular gas.

Spin orbit torque switching in Ta/CoFeB/MgO without longitudinal fields

2015

Intense investigations are carried out on novel magnetic materials systems with perpendicular magnetic anisotropy (PMA), where new spin-orbit effects occur due to structural inversion asymmetry (SIA). So called spin-orbit torques (SOTs), have been observed for the first time in PMA nano-structures with SIA, when an electric current is injected [1-3], leading to ultra-efficient current-induced domain wall motion and current-induced magnetization switching [2,3].

Lateral Electric‐Field‐Controlled Perpendicular Magnetic Anisotropy and Current‐Induced Magnetization Switching in Multiferroic Heterostructures

2020

Martensite transition and microscopic magnetism of epitaxial Ni2MnGa films

2007

AbstractA magnetically induced shape memory effect in Ni2MnGa results in huge magnetostrictive effects of several percent. Using x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) we investigated element specific magnetic moments and electronic structure of single crystalline, (110) oriented Ni2MnGa films on a-plane Al2O3 substrates in the austenite and martensite state. The structural phase transition of the samples is evident from temperature dependent x-ray diffraction and magnetization measurements. The Ni XAS differ significantly for temperatures above and below the martensite transition in agreement with published ab-initio calculations. Using XAS in transmissi…

Spin-orbital polarization of Majorana edge states in oxides nanowires

2020

We investigate a paradigmatic case of topological superconductivity in a one-dimensional nanowire with $d-$orbitals and a strong interplay of spin-orbital degrees of freedom due to the competition of orbital Rashba interaction, atomic spin-orbit coupling, and structural distortions. We demonstrate that the resulting electronic structure exhibits an orbital dependent magnetic anisotropy which affects the topological phase diagram and the character of the Majorana bound states (MBSs). The inspection of the electronic component of the MBSs reveals that the spin-orbital polarization generally occurs along the direction of the applied Zeeeman magnetic field, and transverse to the magnetic and or…

Field-induced slow magnetic relaxation in pseudooctahedral cobalt(ii) complexes with positive axial and large rhombic anisotropy

2019

The preparation, X-ray crystal structure, spectroscopic and variable-temperature dc and ac magnetic properties of two six-coordinate cobalt(ii) complexes of formula [Co(bim)4(tcm)2] (1) and [Co(bmim)4(tcm)2] (2) (bim = 1-benzylimidazole, bmim = 1-benzyl-2-methylbenzimidazole and tcm- = tricyanomethanide ion) are reported. 1 and 2 crystallize in the monoclinic P21/n and C2/c space groups with the asymmetric units composed of one tcm- ion and half the [Co(bim)4]2+ and [Co(bmim)4]2+ complex cations, respectively. Their cobalt atoms are in compressed (1)/rhombic (2) CoN6 octahedral environments, the axial positions being occupied by monodentate tricyanomethanide anions. The neutral molecules in…

Field-Induced Slow Magnetic Relaxation In the First Dy(III)-centered 12-Metallacrown-4 Double-Decker

2019

The reaction of Dy(O2CMe)3·xH2O and Ga(NO3)3·xH2O led to the isolation of (nBu4N)[GaIII8DyIII(OH)4(shi)8] (1). The compound possesses a unique chemical structure enclosing the central magnetic DyIII ion between diamagnetic GaIII-based metallacrown 12-MC-4 ligands. The double-decker complex exhibits field-induced single-molecule magnet (SMM) behaviour with an effective energy barrier (Ueff) of 39 K (27.1 cm−1). Consistent with the observed slow relaxation of magnetization, theoretical calculations suggest a ground state mainly determined by |±11/2> in the easy axis direction.

Giant Spin Seebeck Effect through an Interface Organic Semiconductor

2019

Interfacing an organic semiconductor C60 with a non-magnetic metallic thin film (Cu or Pt) has created a novel heterostructure that is ferromagnetic at ambient temperature, while its interface with a magnetic metal (Fe or Co) can tune the anisotropic magnetic surface property of the material. Here, we demonstrate that sandwiching C60 in between a magnetic insulator (Y3Fe5O12: YIG) and a non-magnetic, strong spin-orbit metal (Pt) promotes highly efficient spin current transport via the thermally driven spin Seebeck effect (SSE). Experiments and first principles calculations consistently show that the presence of C60 reduces significantly the conductivity mismatch between YIG and Pt and the s…

Spin-polarized scanning tunneling microscopy and spectroscopy of ultrathinFe∕Mo(110)films usingW∕Au∕Cotips

2006

We report on magnetic contrast observed in low-temperature spin-polarized scanning tunneling microscopy (SP-STM) of Fe nanowires deposited on Mo(110) using tungsten tips covered by $\mathrm{Au}∕\mathrm{Co}$ thin films. Due to the spin reorientation transition of Co films on Au an out-of-plane magnetic sensitivity is obtained for tips with thin cobalt films (up to 8 monolayers of Co), while for thicker Co coverages an in-plane magnetization component can be probed. Using $\mathrm{W}∕\mathrm{Au}∕\mathrm{Co}$ tips with out-of-plane magnetic sensitivity we show that the one (ML) and two (DL) atomic layers thick Fe nanowires prepared using step flow growth on a Mo(110) crystal are perpendicularl…