The zero-field muon spin relaxation (ZF-mu SR) technique is employed t
o study the magnetic properties of the non-superconducting borocarbide
SmNi2B2C. Coherent ordering of the Sm electronic magnetic moments app
ears below 9.86(3) K, leading to a local field at the muon site of 105
6.2(2)G at 3.3 K. Measurements on superconducting YNi2B2C reveal no ev
idence of either slowing-down of fluctuating or the presence of quasi-
static Ni electronic moments down to 3 K.