STUDIES OF THE MAGNETIC-BEHAVIOR OF ERAL3(BO3)(4) AND THE EFFECTS OF THE CRYSTAL-FIELD

Single crystals of ErAl3(BO3)(4) were produced by flux growing techniq ues. The principal magnetic susceptibility, XI, perpendicular to the s ymmetry axis of the crystal was measured in the range 300-14.2 K, and the principal anisotropy (X parallel to -X perpendicular to) was deter mined from 300 to 77 K, which turned out to be negative throughout. A crystal field conforming to D-3 site symmetry (obtained from structura l data) accounts very well for the observed thermal variation of the m agnetic susceptibilities; this yields g factors, g parallel to and g p erpendicular to, of 2.32 and 8.95, respectively. The electronic heat c apacity is computed, and shows a Schottky anomaly at around 45 K. Calc ulated quadrupole splitting of Er-167 due to crystal field effects sho ws a smooth decrease with decreasing temperature. The hyperfine heat c apacity, contributed mainly by magnetic hyperfine splitting, displays a rounded maximum at about 8 mK. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.