The magnetic phase diagram of the quasi one-dimensional spinchain system CsNiF3 below the N\'eel temperature is determined. For magnetic fields perpendicular to the spin chains incommensurate phases are predicted. From linear spin-wave theory we obtain the instability line of the paramagnetic phase as a function of the strength and the direction of the field. The system undergoes a transition to a commensurate or an incommensurate phase depending on the direction of the magnetic field. In the commensurate phase the characterizing wave vector is locked to values describing a two-sublattice structure, whereas in the incommensurate phase the wave vector changes continuously between the corresponding two-sublattice wave vectors.
@article{arxiv.cond-mat/9701064,
title = {Alternating commensurate-incommensurate structures in the magnetic phase diagram of CsNiF3},
author = {C. Pich and F. Schwabl},
journal= {arXiv preprint arXiv:cond-mat/9701064},
year = {2009}
}
Comments
11 pages, LaTeX, 5 figures, sent to PRB Rapid Communication