Search results for "magnetic anisotropy"

Strain-controlled domain wall injection into nanowires for sensor applications

2021

We investigate experimentally the effects of externally applied strain on the injection of 180$^\circ$ domain walls (DW) from a nucleation pad into magnetic nanowires, as typically used for DW-based sensors. In our study the strain, generated by substrate bending, induces in the material a uniaxial anisotropy due to magnetoelastic coupling. To compare the strain effects, $Co_{40}Fe_{40}B_{20}$, $Ni$ and $Ni_{82}Fe_{18}$ samples with in-plane magnetization and different magnetoelastic coupling are deposited. In these samples, we measure the magnetic field required for the injection of a DW, by imaging differential contrast in a magneto-optical Kerr microscope. We find that strain increases t…

Magnetic properties of the TbMn2 single crystals

1999

Abstract Single crystals of TbMn 2 were grown by the Czochralski method from a levitated melt. Results of electrical resistivity, magnetization in strong magnetic fields along the principal crystallographic directions, AC and DC magnetic susceptibility and the temperature dependence of the lattice parameter are presented.

Threshold photoemission magnetic circular dichroism at the spin-reorientation transition of ultrathin epitaxial Pt/Co/Pt(111)/W(110) films

2009

X-ray magnetic circular dichroism (MCD) is nowadays widely used for the investigation of magnetic properties of surfaces and thin films. Recently, similarly large effects have been observed for UV-VIS MCD effects both in single [1] and two-photon photoemission [2-3]. This threshold MCD effect is directly related to spin-orbit effects present at the Fermi edge. We report on the observation of threshold photoemission magnetic circular dichroism (TPMCD) in one-photon and two-photon photoemission (1PPE and 2PPE) at a Pt-capped ultrathin Co wedge grown on Pt(111)/W(110) using femtosecond laser light. TPMCD measurements result in asymmetries continuously increasing with the sample thickness. This…

Magnetic Skyrmions: Current-Induced Skyrmion Generation through Morphological Thermal Transitions in Chiral Ferromagnetic Heterostructures (Adv. Mate…

2018

Magnetoelectric properties of epitaxialFe3O4thin films on (011) PMN-PT piezosubstrates

2015

We determine the magnetic and magnetotransport properties of 33 nm thick ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ films epitaxially deposited by rf-magnetron sputtering on unpoled (011) ${[{\mathrm{PbMg}}_{1/3}{\mathrm{Nb}}_{2/3}{\mathrm{O}}_{3}]}_{0.68}\ensuremath{-}{[{\mathrm{PbTiO}}_{3}]}_{0.32}$ (PMN-PT) substrates. The magnetoresistance (MR), as well as the magnetization reversal, strongly depend on the in-plane crystallographic direction of the epitaxial (011) ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ film and strain. When the magnetic field is applied along [100], the magnetization loops are slanted and the sign of the longitudinal MR changes from positive to negative around the Verwey transiti…

Role of top and bottom interfaces of a Pt/Co/AlOx system in Dzyaloshinskii-Moriya interaction, interface perpendicular magnetic anisotropy, and magne…

2017

We investigate the role of top and bottom interfaces in inversion symmetry-breaking Pt/Co/AlOx systems by inserting ultra-thin Cu layers. Wedge-type ultrathin Cu layers (0-0.5 nm) are introduced between Pt/Co or Co/AlOx interfaces. Interface sensitive physical quantities such as the interfacial Dzyaloshinskii-Moriya interaction (iDMI) energy density, the interfacial perpendicular magnetic anisotropy (iPMA), and the magneto-optical Kerr effects (MOKE) are systematically measured as a function of Cu-insertion layer thickness. We find that the Cu-insertion layer in the bottom interface (Pt/Co) plays a more important role in iDMI, PMA, and MOKE. In contrast, the top interface (Co/AlOx) noticeab…

Spin Logical and Memory Device Based on the Nonvolatile Ferroelectric Control of the Perpendicular Magnetic Anisotropy in PbZr 0.2 Ti 0.8 O 3 /Co/Pt …

2020

Temperature-driven spin reorientation transition inFe∕Mo(110)nanostructures

2007

Using low-temperature spin polarized scanning tunneling microscopy and spectroscopy, we observed a temperature-driven spin-reorientation transition (SRT) in Fe double layer (DL) nanostructures grown by step-flow growth on Mo(110). Magnetization components along the vertical and horizontal directions were detected with $4∕16$ ML Co∕10 ML $\mathrm{Au}∕\mathrm{W}(110)$ tips with out-of-plane (4 ML Co) and in-plane (16 ML Co) magnetic sensitivities. The magnetic easy axis of the Fe DL nanostructures continuously rotates from the vertical direction at $5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ to an in-plane direction at $20\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The rotation angle is independent …

Thin epitaxial films of the Heusler compound

2005

Abstract We prepared thin films of the Heusler compound Co 2 Cr 0.6 Fe 0.4 Al with the B2 structure on a-plane (1 1  2 ¯  0) Al 2 O 3 by sputtering. Films grown at high temperatures ( T ⩾ 600 ∘ C ) on Al 2 O 3 are fully epitaxial with the (1 1 0) and (1  1 ¯  0) planes of the film parallel to the (1 1  2 ¯  0) and (0 0 0 1) planes of the substrate, respectively. These epitaxial films possess a higher surface roughness than films grown at room temperature. The films show nearly rectangular hysteresis loops with coercive fields of the order of 10 mT. Magnetooptical Kerr measurements show an in-plane anisotropy of the magnetization with the easy axis in { 0 0 1 } direction. Hall measurements s…

Pulsed laser deposition of epitaxial yttrium iron garnet films with low Gilbert damping and bulk-like magnetization

2014

Yttrium iron garnet (YIG, Y [subscript 3]Fe[subscript 5]O[subscript 12]) films have been epitaxially grown on Gadolinium Gallium Garnet (GGG, Gd[subscript 3]Ga[subscript 5]O[subscript 12]) substrates with (100) orientation using pulsed laser deposition. The films were single-phase, epitaxial with the GGG substrate, and the root-mean-square surface roughness varied between 0.14 nm and 0.2 nm. Films with thicknesses ranging from 17 to 200 nm exhibited low coercivity (<2 Oe), near-bulk room temperature saturation moments (∼135 emu cm[superscript −3]), in-plane easy axis, and damping parameters as low as 2.2 × 10[superscript −4]. These high quality YIG thin films are useful in the investigation…