Tuning the Néel temperature in an antiferromagnet: the case of NixCo1−xO microstructures

Abstract We show that it is possible to tune the Néel temperature of nickel(II)-cobalt(II) oxide films by changing the Ni to Co ratio. We grow single crystalline micrometric triangular islands with tens of nanometers thickness on a Ru(0001) substrate using high temperature oxygen-assisted molecular beam epitaxy. Composition is controlled by adjusting the deposition rates of Co and Ni. The morphology, shape, crystal structure and composition are determined by low-energy electron microscopy and diffraction, and synchrotron-based x-ray absorption spectromicroscopy. The antiferromagnetic order is observed by x-ray magnetic linear dichroism. Antiferromagnetic domains up to micrometer width are observed.

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Magnetic Behavior and Chemical Shift of Amorphous Cr2O3

Modern Physics Letters B ◽

10.1142/s0217984997000517 ◽

1997 ◽

Vol 11 (09n10) ◽

pp. 415-420

Author(s):

I. Pop ◽

M. Andrecut ◽

I. Burda ◽

C. Oprea ◽

C. Andrecut

Keyword(s):

Chemical Shift ◽

Temperature Dependence ◽

Linear Dependence ◽

Magnetic Behavior ◽

Neel Temperature ◽

Néel Temperature ◽

Amorphous Oxide ◽

X Ray ◽

X Ray Absorption ◽

Antiferromagnetic Behavior

The chemical shift in cristalline and amorphous Cr2O3 was determined from the X-ray absorption Cr K edge spectra. The measurements of the temperature dependence of the reciprocal susceptibility between 100 and 1200 K show an antiferromagnetic behavior for the cristalline sample, with the Neel temperature at 318 K, and a linear dependence (Curie-Weiss law) with θp<0, for the amorphous oxide.

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X-ray magnetic linear dichroism

Physics Subject Headings (PhySH) ◽

10.29172/6c0dfaf1778e440fb99aad8cbf63c92a ◽

2018 ◽

Keyword(s):

Linear Dichroism ◽

X Ray ◽

Magnetic Linear Dichroism

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Anisotropy of X-ray Absorption Cross Section in CeCoGe3 Single Crystal

Crystals ◽

10.3390/cryst11050544 ◽

2021 ◽

Vol 11 (5) ◽

pp. 544

Author(s):

Andrei Rogalev ◽

Fabrice Wilhelm ◽

Elena Ovchinnikova ◽

Aydar Enikeev ◽

Roman Bakonin ◽

...

Keyword(s):

Cross Section ◽

Absorption Cross Section ◽

Linear Dichroism ◽

X Rays ◽

Absorption Cross ◽

X Ray ◽

Measured Absorption ◽

Linearly Polarized ◽

X Ray Absorption ◽

Absorption Edges

Absorption spectra of two orthogonal linearly polarized x-rays in a single CeCoGe3 crystal were measured at the ID12 beamline of the ESRF for the energies near the K-edges of Ge, Co and near the L23 edges of Ce. The X-ray natural linear dichroism (XNLD) was revealed in the vicinity of all the absorption edges, which indicates a splitting of electronic states in a crystalline field. Mathematical modelling in comparison with experimental data allowed the isotropic and anisotropic parts of atomic absorption cross section in CeCoGe3 to be determined near all measured absorption edges. The calculations also show that the “average” anisotropy of the cross section close to the Ge K-edge revealed in the experiment is less than the partial anisotropic contributions corresponding to Ge atoms in two different Wyckoff positions.

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Single antiferromagnetic axis of Fe in orthorhombic YMn0.5Fe0.5O3 films observed by x-ray magnetic linear dichroism

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2018.11.226 ◽

2019 ◽

Vol 780 ◽

pp. 79-84

Author(s):

Shu Chih Haw ◽

Chang Yang Kuo ◽

Zhiwei Hu ◽

Je Wei Lin ◽

Jenn Min Lee ◽

...

Keyword(s):

Linear Dichroism ◽

X Ray ◽

Magnetic Linear Dichroism

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Extended X-ray Absorption Fine Structure Studies of GaN Epilayers Doped in situ with Er and Eu During Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-798-y5.10 ◽

2003 ◽

Vol 798 ◽

Cited By ~ 3

Author(s):

V. Katchkanov ◽

J. F. W. Mosselmans ◽

S. Dalmasso ◽

K. P. O'Donnell ◽

R. W. Martin ◽

...

Keyword(s):

Fine Structure ◽

Rare Earth ◽

Molecular Beam Epitaxy ◽

Local Structure ◽

Molecular Beam ◽

X Ray ◽

Absorption Fine ◽

X Ray Absorption ◽

The Eu

ABSTRACTThe local structure around Er and Eu atoms introduced into GaN epilayers was studied by means of Extended X-ray Absorption Fine Structure above the appropriate rare-earth X-ray absorption edge. The samples were doped in situ during growth by Molecular Beam Epitaxy. The formation of ErN clusters was found in samples with high average Er concentrations of 32±6% and 12.4±0.8%, estimated by Wavelength Dispersive X-ray analysis. When the average Er concentration is decreased to 6.0±0.2%, 1.6±0.2% and 0.17±0.02%, Er is found in localised clusters of ErGaN phase with high local Er content. Similar behaviour is observed for Eu-doped samples. For an average Eu concentration of 30.5±0.5% clusters of pure EuN occur. Decreasing the Eu concentration to 10.4±0.5% leads to EuGaN clusters with high local Eu content. However, for a sample with an Eu concentration of 14.2±0.5% clustering of Eu was not observed.

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A single crystal, linearly polarized Fe 2p X-ray absorption study of gillespite

Mineralogical Magazine ◽

10.1180/002646198547477 ◽

1998 ◽

Vol 62 (1) ◽

pp. 65-75 ◽

Cited By ~ 7

Author(s):

P. F. Schofield ◽

G. van der Laan ◽

C. M. B. Henderson ◽

G. Cressey

Keyword(s):

Single Crystal ◽

Ground State ◽

Branching Ratio ◽

Linear Dichroism ◽

Electronic Charge ◽

Magic Angle ◽

X Rays ◽

X Ray ◽

Peak Structure ◽

X Ray Absorption

AbstractThe Fe 2p X-ray absorption spectra of single crystal gillespite, BaFeSi4O10, show a strong linear dichroism, i.e. a large difference in the absorption when measured with the polarization of the X-rays either parallel or perpendicular to the plane of the FeO4 group. The isotropic spectrum, obtained from measurement at the ‘magic angle’, and the polarization dependent spectra have been compared to atomic multiplet calculations and show an excellent agreement with theory. Analysis of the branching ratio, the linear dichroism, and the detailed peak structure confirms that the 5A1 level is the ground state at room temperature and pressure. The 5B2 level is sufficiently low in energy that a distortion of the electronic charge density, induced by increased pressure, may result in a 5B2 ground state.

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Near Edge X-Ray Absorption Fine Structure (NEXAFS) Microscopy: Chemical Analysis at Sub Visible Spatial Resolution

Microscopy and Microanalysis ◽

10.1017/s1431927600011144 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 851-852

Author(s):

H. Ade

Keyword(s):

Fine Structure ◽

Compositional Analysis ◽

High Sensitivity ◽

Linear Dichroism ◽

X Rays ◽

X Ray ◽

Absorption Fine ◽

Nexafs Spectroscopy ◽

Wide Range ◽

X Ray Absorption

Infrared, Raman, and fluorescence/luminescence microspectroscopy/microscopy in many instances seek to provide high sensitivity compositional and functional information that goes beyond mere elemental composition. This goal is shared by NEXAFS microscopy, in which Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is employed to provide chemical sensitivity and can be relatively easily adopted in a scanning transmission x-ray microscope (STXM). In addition to compositional information, NEXAFS microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays (linear dichroism microscopy). For compositional analysis, NEXAFS microscopy is analogous to Electron Energy Loss Spectroscopy (EELS) in an electron microscope. However, when utilizing near edge spectral features, NEXAFS microscopy requires a considerable lower dose than EELS microscopy which makes it very suitable to studying radiation sensitive materials such as polymers. NEXAFS has shown to have excellent sensitivity to a wide range of moieties in polymers, including sensitivity to substitution isomerism.

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