Internet Archive Scholar

Inelastic neutron scattering studies on the odd-membered antiferromagnetic wheel Cr8Ni

Michael L. Baker, Oliver Waldmann, Stergios Piligkos, Roland Bircher, Olivier Cador, Stefano Carretta, David Collison, Felix Fernandez-Alonso, Eric J. L. McInnes, Hannu Mutka, Andrew Podlesnyak, Floriana Tuna (+7 others)
2012 Physical Review B  

Preserved Fulltext

fulltext thumbnail
Web Archive Capture PDF (1.7 MB)
https://web.archive.org/web/20180726141819/https://hal.archives-ouvertes.fr/hal-00847048/file/PhysRevB.86.064405.pdf

A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2018; you can also visit the original URL. The file type is application/pdf.

i C 3 H 7 ) 2 NH 2 ][Cr 8 NiF 9 (O 2 CCMe) 18 ], or Cr 8 Ni, is a prominent example of an odd-membered antiferromagnetic "wheel." A detailed characterization of the magnetic properties of Cr 8 Ni has been conducted. Inelastic neutron scattering (INS) is used to investigate the energy and momentum transfer dependence of the low-lying spin excitations, including excited states inaccessible by other experimental techniques. The richness of the INS data, in conjunction with microscopic spin
more » ... ian simulations, enables an accurate characterization of the magnetic properties of Cr 8 Ni. Nearest-neighbor exchange constants of J CrCr = 1.31 meV and J CrNi = 3.22 meV are determined, and clear evidence of axial single-ion anisotropy is found. The parameters determined by INS are shown to fit magnetic susceptibility. The spectroscopic identification of several successive S = 1 excited total spin states and lowest spin band excitations show that the rotational band picture, valid for bipartite AFM wheels, breaks down for this odd-numbered wheel. The exchange constants determined here differ from previous efforts based on bulk measurements, and possible reasons are discussed. The large J CrNi /J CrCr ratio in Cr 8 Ni puts this wheel into a regime with strong quantum fluctuations in which the ground state can be described with a valence bond solid state picture.
doi:10.1103/physrevb.86.064405 fatcat:g6lfhsxwkrc5fdssc6xzemqeoy
Citation

Michael L. Baker, Oliver Waldmann, Stergios Piligkos, Roland Bircher, Olivier Cador, Stefano Carretta, David Collison, Felix Fernandez-Alonso, Eric J. L. McInnes, Hannu Mutka, Andrew Podlesnyak, Floriana Tuna, Stefan Ochsenbein, Roberta Sessoli, Andreas Sieber, Grigore A. Timco, Høgni Weihe, Hans U. Güdel, Richard E. P. Winpenny. "Inelastic neutron scattering studies on the odd-membered antiferromagnetic wheel Cr8Ni." Physical Review B 86.6 (2012)