TY  - JOUR
AU  - Kozłowski, Paweł
AU  - Fabrykiewicz, Piotr
AU  - Sosnowska, Izabela
AU  - Fauth, François
AU  - Senyshyn, Anatoliy
AU  - Suard, Emmanuelle
AU  - Oleszak, Dariusz
AU  - Przeniosło, Radosław
TI  - Monoclinic symmetry of the hcp-type ordered areas in bulk cobalt
JO  - Physical review / B
VL  - 107
IS  - 10
SN  - 2469-9950
CY  - College Park, Maryland
PB  - Americal Physical Society
M1  - FZJ-2023-04627
SP  - 104104
PY  - 2023
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000964159000003
DO  - DOI:10.1103/PhysRevB.107.104104
UR  - https://juser.fz-juelich.de/record/1018231
ER  -