~(166)Er Moessbauer spectroscopy study of magnetic ordering in a spinel-based potential spin-ice system: CdEr_2S_4

摘要

~(166)Er Moessbauer spectroscopy measurements of CdEr_2S_4 show a large hyperfine field (B_(hf)) of 727.6(8) T at 5 K and clear evidence for slow paramagnetic relaxation with an energy barrier to reversal of 114(3) K. This behaviour stands in strong contrast to that of the corresponding pyrochlores (Er_2Sn_2O_7 and Er_2Ti_2O_7) where no magnetic effects are seen down to 1.56 K. The clearly dynamic ~(166)Er Moessbauer spectra and the absence of a break in the susceptibility data suggest that there is no magnetic order above 1.8 K in CdEr_2S_4.