1H nuclear magnetic resonance (NMR) and relaxation measurements have been performed in the Keplerate species Mo72Fe30. The 1H NMR linewidth increases gradually with decreasing T and it saturates below about 4 K, as expected for a nonmagnetic ground state with S T=0. A strong enhancement of T 1 -1 with a peak around T=2K is observed, a feature similar to the one observed in antiferromagnetically (AF) coupled iron rings. The peak is discussed in terms of the slowing down of magnetic fluctuations resulting from building up of AF correlations.
ASJC Scopus subject areas
- Physics and Astronomy(all)