We present single crystal inelastic neutron scattering measurements of the S=1 dimerized quasi-two-dimensional antiferromagnet Ba3Mn2O8. The singlet-triplet dispersion reveals nearest-neighbor and next-nearest-neighbor ferromagnetic interactions between adjacent bilayers that compete against each other. Although the inter-bilayer exchange is comparable to the intra-bilayer exchange, this additional frustration reduces the effective coupling along the c-axis and leads to a quasi-two dimensional behavior. In addition, the obtained exchange values are able to reproduce the four critical fields in the phase diagram.
Cite
@article{arxiv.0804.4437,
title = {Singlet-triplet dispersion reveals additional frustration in the triangular dimer compound Ba$_3$Mn$_2$O$_8$},
author = {M. B. Stone and M. D. Lumsden and S. Chang and E. C. Samulon and C. D. Batista and I. R. Fisher},
journal= {arXiv preprint arXiv:0804.4437},
year = {2009}
}
Comments
4 pages, 3 color figures, submitted to an APS physical review journal