Fast Field Cycling Study of AC Magnetic Induced Spectral Densities in doped gelatins

F. BONETTO; E. ANOARDO; D. PUSIOL

Berlin, Alemania

Simposio; Symposium on field Cycling NMR Relaxometry; 1998

Groupment AMPERE, Intenational Society of Magnetic Resonance (ISMAR)

In this work we report a study about the influence of an external AC magnetic perturbation in the spin-lattice relaxation time of nano-size ferromagnetic doped gelatins (ferrogelatin). For comparison, we studied the same effect in a sample without dopants. Because of the effect we aimed to observe was maximum when the perturbation and Larmor frequencies were coincident, the evolution of the proton magnetization contained information about two processes: the spin-lattice relaxation and spin energy absortion from the perturbing magnetic field. As we was only interested in externally induced dynamical processes (observable through the proton spin-lattice relaxation), we had to discriminate both effects. Fast field cycling NMR experiments combined with sinusoidal magnetic low frequency perturbation were used to study this phenomena