Questioning Antiferromagnetic Ordering in the Expanded Metal, Li(NH3)4: A Lack of Evidence from μSR

Andrew G Seel; Peter J Baker; Stephen P Cottrell; Christopher A Howard; Neal T Skipper; Peter P Edwards

doi:10.1021/acs.jpclett.5b01380

Questioning Antiferromagnetic Ordering in the Expanded Metal, Li(NH3)4: A Lack of Evidence from μSR

J Phys Chem Lett. 2015 Oct 1;6(19):3966-70. doi: 10.1021/acs.jpclett.5b01380. Epub 2015 Sep 21.

Authors

Andrew G Seel^{1

2}, Peter J Baker¹, Stephen P Cottrell¹, Christopher A Howard³, Neal T Skipper^{3

4}, Peter P Edwards²

Affiliations

¹ ISIS Spallation Neutron and Muon Source , Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom.
² Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom.
³ Department of Physics and Astronomy, University College London , Gower Street, London WC1E 6BT, United Kingdom.
⁴ London Centre for Nanotechnology , 19 Gordon Street, London WC1H 0AH, United Kingdom.

PMID: 26722900
DOI: 10.1021/acs.jpclett.5b01380

Abstract

We present the results of a muon spin relaxation study of the solid phases of the expanded metal, Li(NH3)4. No discernible change in muon depolarization dynamics is witnessed in the lowest temperature phase (≤25 K) of Li(NH3)4, thus suggesting that the prevailing view of antiferromagnetic ordering is incorrect. This is consistent with the most recent neutron diffraction data. Discernible differences in muon behavior are reported for the highest temperature phase of Li(NH3)4 (82-89 K), attributed to the onset of structural dynamics prior to melting.

Keywords: expanded metals; lithium; magnetism; molecular metals; muon spin relaxation; solvated electron.