Dimer splitting of Er3+ in Cs3Er2Br9

Inelastic neutron scattering (INS) measurements were performed on the rare earth dimer compound Cs,Er,Br,. The crystalline electric field (CEF) parame ters were determined. The lack of any exchange splitting associated with th e CEF transitions can be explained by the large single ion anisotropy for E r. An energy level scheme is proposed, which was tested with extensive magn etization and specific heat measurements as a function of temperature and m agnetic field. (C) 2001 Elsevier Science B.V. All rights reserved.