%0 Journal Article
%A Kozłowski, Paweł
%A Fabrykiewicz, Piotr
%A Sosnowska, Izabela
%A Fauth, François
%A Senyshyn, Anatoliy
%A Suard, Emmanuelle
%A Oleszak, Dariusz
%A Przeniosło, Radosław
%T Monoclinic symmetry of the hcp-type ordered areas in bulk cobalt
%J Physical review / B
%V 107
%N 10
%@ 2469-9950
%C College Park, Maryland
%I Americal Physical Society
%M FZJ-2023-04627
%P 104104
%D 2023
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000964159000003
%R 10.1103/PhysRevB.107.104104
%U https://juser.fz-juelich.de/record/1018231