English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Neutron and x-ray powder and single crystal synchrotron diffraction ofCsyFe2-xSe2 show the presence of superstructure reflections with propagationvector k=[2/5, 1/5, 1] with respect to the average crystal structure I4/mmm (a= 4, c = 15A). The propagation vector star corresponds to the 5 times biggerunit cell given by transformation A=2a+b, B= -a+2b, C= c. A solution for theatomic structure is found in the space groups P42/n and I4/m with an orderedpattern of iron vacancies corresponding to the iron deficiency x = 0.29 and Csstoichiometry y = 0.83. The superstructure satellites are more pronounced inthe neutron diffraction patterns suggesting that they can have some magneticcontribution. We have sorted out possible symmetry adapted magneticconfigurations and found that the presence of AFM ordering with the orderedmagnetic moment of Fe with 2{\mu}B does not contradict to the experimentaldata. However, the solutions space is highly degenerate and we cannot choose aspecific solution. Instead we propose possible magnetic configurations with theFe magnetic moments in (ab)-plane or along c-axis. The superstructure isdestroyed above Ts ~ 500 K by a first-order-like transition.

Iron vacancy superstructure and possible room temperature antiferromagnetic order in superconducting Cs_{y}Fe_{2-x}Se_2