The spin dynamics of a cluster of four iron(III) ions characterized by a total spin ground state S-T = 5 and Ising anisotropy have been investigated by the H-1 nuclear magnetic resonance (NMR) linewidth and H-1 NMR spin-lattice relaxation rate 1/T-1 as a function of the temperature (0.5-295 K) and external magnetic field (0.3-7.2 T). At very low T (0.5 K) the spectrum becomes very broad indicating freezing of the Fe3+ moments in a superparamagnetic state. The temperature dependence of T-1(-1) and T-2(-1) shows strong field dependent enhancement below 50 K which must be related to the spin dynamics of the Fe3+ moment freezing process, although no quantitative theory of this is currently available.
H-1 nuclear magnetic resonance and spin dynamics in the tetranuclear iron(III) cluster {Fe-4} / Procissi, D.; Suh, B. J.; Lascialfari, A.; Borsa, F.; Caneschi, Andrea; Cornia, A.. - In: JOURNAL OF APPLIED PHYSICS. - ISSN 0021-8979. - STAMPA. - 91:(2002), pp. 7173-7175. [10.1063/1.1450790]
H-1 nuclear magnetic resonance and spin dynamics in the tetranuclear iron(III) cluster {Fe-4}
CANESCHI, ANDREA;
2002
Abstract
The spin dynamics of a cluster of four iron(III) ions characterized by a total spin ground state S-T = 5 and Ising anisotropy have been investigated by the H-1 nuclear magnetic resonance (NMR) linewidth and H-1 NMR spin-lattice relaxation rate 1/T-1 as a function of the temperature (0.5-295 K) and external magnetic field (0.3-7.2 T). At very low T (0.5 K) the spectrum becomes very broad indicating freezing of the Fe3+ moments in a superparamagnetic state. The temperature dependence of T-1(-1) and T-2(-1) shows strong field dependent enhancement below 50 K which must be related to the spin dynamics of the Fe3+ moment freezing process, although no quantitative theory of this is currently available.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
