FLUCTUATION-INDUCED PHASE IN CSCUCL3 IN A TRANSVERSE MAGNETIC-FIELD -EXPERIMENT

The new magnetic phase of CsCuCl3 recently found by specific heat meas urements has been investigated by means of neutron diffraction. This n ew phase is found very close to the critical temperature and it widens to a few tenths of a degree Kelvin in very high magnetic fields. The availability of a new strong steady-state magnet with a nominal streng th of 14.5 T provided us with the opportunity to investigate the magne tic structure. We found that the new phase is also incommensurate, but that it no longer has the 120 degrees triangular antiferromagnetic st ructure. A proposal for the structure derived from a Landau theory put forward in the following theory paper by Jacobs and Nikuni is compare d to the experimental results. The order of the transitions observed w ill be discussed, as well as our failure to observe a predicted commen surate phase.