ISIS Neutron and Muon Source Data Journal

Spin dynamics and magnetic ordering in the p-orbital molecular solids CsO2 and NaO2

Abstract: A magnetic response of the alkali-metal superoxides comes from the p-orbital S = 1/2 spins of anionic O2- molecules. As the O2- molecules are highly reorientable and the corresponding degenerate p orbitals are prone to orbital ordering, these structurally very simple systems exhibit surprisingly complex physics. In CsO2, the p-orbital ordering leading to the formation of spin-1/2 chains below 70 K and a subsequent low-temperature magnetic ordering below 10 K are well established, but the magnetic structure of the ordered phase remains unknown. In NaO2, our NMR results reveal a series of crossovers between different spin-fluctuating regimes below 180 K, but with no signs of magnetic ordering. To address different spin-fluctuating regimes in CsO2 and NaO2 and to unambiguously answer the questions of the existence of the low-temperature magnetic order in NaO2, we are proposing a muSR study.

Principal Investigator: Dr Andrej Zorko
Experimenter: Dr Martin Klanjsek
Local Contact: Dr Pabitra Biswas
Experimenter: Dr Martin Jansen
Experimenter: Mr Adler
Experimenter: Dr Denis Arcon
Experimenter: Professor Matja? Gomil?ek
Experimenter: Mr Tilen Knaflic
Experimenter: Dr Peter Adler

DOI: 10.5286/ISIS.E.RB1610205

ISIS Experiment Number: RB1610205

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Dr Andrej Zorko et al; (2016): Spin dynamics and magnetic ordering in the p-orbital molecular solids CsO2 and NaO2, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB1610205

Data is released under the CC-BY-4.0 license.