We present the results of high-field magnetization and muon-spin relaxation measurements on the coordination polymer CuF_2(H_2O)_2(pyrazine) in pressures up to 22.5 kbar. We observe a transition from a quasi-two-dimensional to a quasi-one-dimensional antiferromagnetic phase at 9.1 kbar, driven by a rotation of the Jahn-Teller axis. Long-range antiferromagnetic ordering is seen in both regimes, as well as a phase separation in the critical pressure region. The magnetic dimensionality switching as pressure is increased is accompanied by a halving of the primary magnetic exchange energy J and a fivefold decrease in the ordering temperature T_N. J decreases gradually with pressure in the two-dimensional phase, and then increases in the one-dimensional regime. We relate both effects to the changes in the crystal structure with applied pressure.
@article{arxiv.1304.5403,
title = {Evolution of magnetic interactions in a pressure-induced Jahn-Teller driven magnetic dimensionality switch},
author = {S. Ghannadzadeh and J. S. Möller and P. A. Goddard and T. Lancaster and F. Xiao and S. J. Blundell and A. Maisuradze and R. Khasanov and J. L. Manson and S. W. Tozer and D. Graf and J. A. Schlueter},
journal= {arXiv preprint arXiv:1304.5403},
year = {2013}
}
Comments
5 pages, 3 figures, supplemental material included