Structural Order in Heusler Compounds

Wurmehl, S.; Wójcik, Marek J.

doi:10.1007/978-3-319-21449-8_4

Cited by 9 publications

(3 citation statements)

References 87 publications

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“…Because the shape of resonance spectrum is sensitive to the change of hyperfine field reflecting the local environment. Chemical degree of order as well as the chemical composition can be quantitatively evaluated using NMR: e.g., Wurmehl et al carried out an NMR study on Co 2 Mn 1-x Fe x Si Heusler alloys with several Fe composition x in the bulk samples, and quantitatively evaluated the chemical ordering especially focusing on the distribution of Fe-Mn atoms using spin-echo NMR of 55 Mn nuclei [228]. The chemical ordering between Fe and Mn is not easy to characterise using, e.g., laboratory X-rays because the atomic numbers of those are close each other, thus NMR is useful for characterising Heusler alloys which often consists of atoms with similar atomic numbers.…”

Section: Nuclear Magnetic Resonancementioning

confidence: 99%

Heusler alloys for spintronic devices: review on recent development and future perspectives

Elphick

Frost

Samiepour

et al. 2021

Science and Technology of Advanced Materials

255

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Heusler alloys are theoretically predicted to become half-metals at room temperature (RT). The advantages of using these alloys are good lattice matching with major substrates, high Curie temperature above RT and intermetallic controllability for spin density of states at the Fermi energy level. The alloys are categorised into half- and full-Heusler alloys depending upon the crystalline structures, each being discussed both experimentally and theoretically. Fundamental properties of ferromagnetic Heusler alloys are described. Both structural and magnetic characterisations on an atomic scale are typically carried out in order to prove the half-metallicity at RT. Atomic ordering in the films is directly observed by X-ray diffraction and is also indirectly probed via the temperature dependence of electrical resistivity. Element specific magnetic moments and spin polarisation of the Heusler alloy films are directly measured using X-ray magnetic circular dichroism and Andreev reflection, respectively. By employing these ferromagnetic alloy films in a spintronic device, efficient spin injection into a non-magnetic material and large magnetoresistance are also discussed. Fundamental properties of antiferromagnetic Heusler alloys are then described. Both structural and magnetic characterisations on an atomic scale are shown. Atomic ordering in the Heusler alloy films is indirectly measured by the temperature dependence of electrical resistivity. Antiferromagnetic configurations are directly imaged by X-ray magnetic linear dichroism and polarised neutron reflection. The applications of the antiferromagnetic Heusler alloy films are also explained. The other non-magnetic Heusler alloys are listed. A brief summary is provided at the end of this review.

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Section: Nuclear Magnetic Resonancementioning

confidence: 99%

Heusler alloys for spintronic devices: review on recent development and future perspectives

Elphick

Frost

Samiepour

et al. 2021

Science and Technology of Advanced Materials

255

View full text Add to dashboard Cite

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“…In this structure, the first sublattice is formed with X atoms intermixed with Y atoms and the second—with X atoms intermixed with Z atoms. However, this type of atomic order is very uncommon to be experimentally realized [ 34 ]. On the other hand, significant variations in the intensities of the (200) and (311) reflections could be achieved in the case of so-called DO 3 or X -type disorders [ 35 ].…”

Section: Resultsmentioning

confidence: 99%

Control of Structural and Magnetic Properties of Polycrystalline Co2FeGe Films via Deposition and Annealing Temperatures

et al. 2021

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Thin polycrystalline Co2FeGe films with composition close to stoichiometry have been fabricated using magnetron co-sputtering technique. Effects of substrate temperature (TS) and post-deposition annealing (Ta) on structure, static and dynamic magnetic properties were systematically studied. It is shown that elevated TS (Ta) promote formation of ordered L21 crystal structure. Variation of TS (Ta) allow modification of magnetic properties in a broad range. Saturation magnetization ~920 emu/cm3 and low magnetization damping parameter α ~ 0.004 were achieved for TS = 573 K. This in combination with soft ferromagnetic properties (coercivity below 6 Oe) makes the films attractive candidates for spin-transfer torque and magnonic devices.

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“…The crystallinity of Heusler alloy is always an important issue [4][5][6][7]. The ideal crystal structure of Co 2 YZ type full * Author to whom any correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

High-density magnetic-vacancy inclusion in Co₂MnGa single crystal probed by spin-polarized positron annihilation spectroscopy

Miyashita¹,

Maekawa²,

Shimoyama³

et al. 2021

J. Phys.: Condens. Matter

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Co2MnGa is a Weyl semimetal exhibiting giant anomalous Hall and Nernst effects. Using spin-polarized positron annihilation spectroscopy, we examined a Bridgman-grown Co2MnGa single crystal with a nearly perfect L21-ordered structure and a reference Co2MnAl polycrystal with a Mn-Al-disordered B2 structure. We found that a large amount of magnetic vacancies (more than 100 ppm) were included in the Co2MnGa crystal but not the Co2MnAl crystal. We discuss possible reasons for the inclusion of vacancies, the role of vacancies in the development of the ordered structure, and the electronic states associated with the vacancies. Towards the development of Co2MnGa-based devices, the manners for reducing vacancies as well as the influence of vacancies on the electrical transport properties should be considered.

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Structural Order in Heusler Compounds

Cited by 9 publications

References 87 publications

Heusler alloys for spintronic devices: review on recent development and future perspectives

Heusler alloys for spintronic devices: review on recent development and future perspectives

Control of Structural and Magnetic Properties of Polycrystalline Co2FeGe Films via Deposition and Annealing Temperatures

High-density magnetic-vacancy inclusion in Co₂MnGa single crystal probed by spin-polarized positron annihilation spectroscopy

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Structural Order in Heusler Compounds

Cited by 9 publications

References 87 publications

Heusler alloys for spintronic devices: review on recent development and future perspectives

Heusler alloys for spintronic devices: review on recent development and future perspectives

Control of Structural and Magnetic Properties of Polycrystalline Co2FeGe Films via Deposition and Annealing Temperatures

High-density magnetic-vacancy inclusion in Co2MnGa single crystal probed by spin-polarized positron annihilation spectroscopy

Contact Info

Product

Resources

About

High-density magnetic-vacancy inclusion in Co₂MnGa single crystal probed by spin-polarized positron annihilation spectroscopy