Journal Article

FZJ-2023-04627

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Monoclinic symmetry of the hcp-type ordered areas in bulk cobalt

Kozłowski, P. ; Fabrykiewicz, P.MLZ*RWTH*FZJ* ; Sosnowska, I. ; Fauth, F. ; Senyshyn, A.MLZ*TUM* ; Suard, E. ; Oleszak, D. ; Przeniosło, R. (Corresponding author)

2023
Americal Physical Society College Park, Maryland

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Please use a persistent id in citations: doi:10.1103/PhysRevB.107.104104  doi:10.34734/FZJ-2023-04627

Abstract: The gradual ferromagnetic spin reorientation in hexagonal close packed cobalt (hcp-Co) phase between 230 $^\circ$C and 330 $^\circ$C reported for a Co single crystal [Bertaut $\textit{et al.}$, Solid State Commun. $\textbf{1}$, 81 (1963)] suggests that this phase could not have a hexagonal symmetry. This hypothesis is verified positively by synchrotron radiation diffraction and neutron diffraction on polycrystalline powder cobalt. The analysis of diffraction data has been done by using a specific set of Bragg peaks, which are not sensitive to the stacking faults present in abundance in hcp-Co. The crystal structure of the hcp-type ordered areas of cobalt is described by the monoclinic symmetry with the magnetic space group $C2'/m'$. In this monoclinic crystal structure the former hexagonal $[001]$ axis is no longer perpendicular to the hexagonal layers. The hexagonal $[001]$ and $[010]$ axes make an angle equal $\alpha \approx 90.10(1)$ $^\circ$, while the angle between in-plane $[100]$ and $[010]$ axes equals $\gamma \approx 120.11(1)$ $^\circ$. The monoclinic symmetry provides an approximate description of the crystal structure of the stacking faulted hcp-Co areas coexisting with fcc-Co areas.

Keyword(s): Magnetic Materials (1st) ; Crystallography (2nd) ; Magnetism (2nd) ; Condensed Matter Physics (2nd) ; Materials Science (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. JARA-FIT (JARA-FIT)
3. Streumethoden (JCNS-2)
4. Heinz Maier-Leibnitz Zentrum (MLZ)
5. JCNS-4 (JCNS-4)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)
2. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)

Experiment(s):

1. SPODI: High resolution powder diffractometer (SR8a)
2. Measurement at external facility

Appears in the scientific report 2023

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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