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Spin dynamics of the giant polyoxometalate molecule {Mn40W224} studied by NMR

TitleSpin dynamics of the giant polyoxometalate molecule {Mn40W224} studied by NMR
Publication TypeJournal Article
Year of Publication2014
AuthorsFurukawa, Y, Fang, X, Kogerler, P
JournalJournal of Physics-Condensed Matter
Date Published05
Type of ArticleArticle
ISBN Number0953-8984
Accession NumberWOS:000335825000010
Keywordscluster, magnetization, molecular magnet, nmr, spin dynamics

Li-7 nuclear magnetic resonance (NMR) studies have been performed to investigate magnetic properties and spin dynamics of Mn3+ (S = 2) spins in the giant polyoxometalate molecule {Mn40W224}. The Li-7-NMR line width is proportional to the external magnetic field H as expected in a paramagnetic state above 3 K. Below this temperature the line width shows a sudden increase and is almost independent of H, which indicates freezing of the local Mn3+ spins. The temperature dependence of T-1 for both H-1 and Li-7 reveals slow spin dynamics at low temperatures, consistent with spin freezing. The slow spin dynamics is also evidenced by the observation of a peak of 1/T-2 around 3 K, where the fluctuation frequency of spins is of the order of similar to 200 kHz. An explicit form of the temperature dependence of the fluctuation frequency of Mn3+ spins is derived from the nuclear relaxation data.

Custom 1

Nanoscale and Ultrafast

Custom 2

Complex States