MAGNETIC-RESONANCE STUDIES OF ND3+ AND CE3+ IN LANTHANUM NICOTINATE DIHYDRATE

Electron paramagnetic resonance spectra of nearest neighbour pairs hav e been measured for the light lanthanide ions Ce3+ and Nd3+ in lanthan ide nicotinate dihydrates, for comparison with the properties of the h eavy lanthanide (HLn) ions Tm3+, Dy3+, Tb3+ and Er3+ Their properties are found to be quite different: (a) the g-matrices have one small and two large principal values in contrast to one large and two very smal l for HLn, (b) the g-matrix is much less changed by replacing a neares t neighbour in a dimer containing two Ln(3+) ions by a La3+ ion than f or HLn and (c) the interaction between a nearest neighbour pair has a large non-dipolar component in contrast to almost purely dipolar inter action for HLn.