Nonmagnetic-magnetic transition and magnetically ordered structure in SmS

SmS, a prototypical intermediate valence compound, has been studied by performing high-pressure nuclear magnetic resonance measurements on $^{33}$S-enriched sample. The observation of an additional signal below 15-20 K above nonmagnetic-magnetic transition pressure $P_{\rm c2} \approx 2$ GPa gives evidence transition. absence Curie-term in the Knight shift near c2}$ indicates that localized character $4f$ electrons is entirely screened and mechanism ordering not described within simple model. Simultaneously, line shape magnetically ordered state incompatible with spin density wave order. These suggest order SmS may require understanding beyond conventional framework for heavy fermions. fact hyperfine fields from moments cancel out at S site leads us to conclusion phase type II antiferromagnetic structure.