Metamagnetic phase transitions in ErCo3 investigated with microscopic methods

Abstract We studied 59 Co nuclear magnetic resonance (NMR) in ErCo 3 in magnetic fields up to B 0 =7 T and at temperatures from 4.2 to 130 K , including the metamagnetic transition at T M =100 K . The hyperfine field B hf is negative only for the Co 18h-site, at 3b- and 6c-Co it is dominated by an unquenched angular momentum. The temperature dependence of the 18h-Co sublattice magnetization is smaller than deduced in a neutron study, with a first-order step at T M . A rapid decrease in NMR line intensity above ≈40 K may indicate a magnetic instability of 3b-Co.