The field-induced magnetic order in the singlet-ground-state system CsFeCl3 has been studied by measuring magnetization and neutron diffraction. The field dependence of intensity for the neutron magnetic reflection has clearly demonstrated that the field-induced ordered phase is described by the order parameter <Sx>. A condensate growth of magnons is investigated through the temperature dependence of Mz and M⊥, and this ordering is discussed in the context of a magnon Bose-Einstein condensation. Development of the coherent state and the static correlation length has been observed in the incommensurate phase in the field region of 5<H<6 T at 1.8 K. At H>Hc, a satellite peak was found in coexistence with the commensurate peak at the phase boundary around 10 T, which indicates that the tilt of the c-axis would be less than ∼0.5∘ in the whole experiments.
@article{arxiv.cond-mat/0407196,
title = {Study of Field-Induced Magnetic Order in Singlet-Ground-State Magnet CsFeCl$_3$},
author = {Mitsuru Toda and Yutaka Fujii and Shinji Kawano and Takao Goto and Meiro Chiba and Shizumasa Ueda and Kenji Nakajima and Kazuhisa Kakurai and Jens Klenke and Ralf Feyerherm and Matthias Meschke and Hans Anton Graf and Michael Steiner},
journal= {arXiv preprint arXiv:cond-mat/0407196},
year = {2009}
}