Er-166 Mossbauer spectroscopy study of magnetic ordering in a spinel-based potential spin-ice system: CdEr2S4

Abstract : Er-166 Mossbauer spectroscopy measurements of CdEr2S4 show a large hyperfine field (B-hf) of 727.6(8) T at 5K 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 (Er2Sn2O7 and Er2Ti2O7) where no magnetic effects are seen down to 1.56 K. The clearly dynamic Er-166 Mossbauer spectra and the absence of a break in the susceptibility data suggest that there is no magnetic order above 1.8K in CdEr2S4. (C) 2015 AIP Publishing LLC.