Determination of the exchange parameters in the frustrated Cairo pentagon lattice compound Bi2Fe4O9.
The Cairo lattice is a tiling of irregular pentagons, each with 4 long and 1 short sides, with magnetic ions at the vertices, thus producing two competing nearest neighbour interactions. When the short bond interaction dominates, a collinear structure is predicted by theory for low spins. For classicals spins, a different structure with the spins forming an orthogonal arrangement that are rotated slightly between the two sublattices is expected. This is the structure found in Bi2Fe4O9 where Fe3+ (S=5/2) spins form a Cairo lattice in the a-b plane. Ab initio calculations and previous inelastic neutron scattering measurements confirmed that the short interaction is strongest. However, the measurements were made in the (hhl) plane and so could not clearly determine the in plane exchange interactions in full. In addition they found a large interlayer coupling and large spin anisotropy gap which warrants further investigation. We thus propose to measure the magnon spectrum in the (hk0) plane on IN20 to elucidate where in the theoretical phase diagram Bi2Fe4O9 falls.
Please note that you will need to login with your ILL credentials to download the data.
Download DataThe recommended format for citing this dataset in a research publication is in the following format:
LE Manh Duc; ENDERLE Mechthild; TSIRLIN Alexander and WHEELER Elisa. (2015). Determination of the exchange parameters in the frustrated Cairo pentagon lattice compound Bi2Fe4O9.. Institut Laue-Langevin (ILL) doi:10.5291/ILL-DATA.4-01-1428
ILL has partnered with DataCite as the registration agency
for data persistent identifiers.