Magnetization and spin dynamics of a Cr-based magnetic cluster: Cr$_{7}$Ni

Authors :: Bianchi, A.
Carretta, S.
Santini, P.
Amoretti, G.
Furukawa, Y.
Kiuchi, K.
Ajiro, Y.
Narumi, Y.
Kindo, K.
Lago, J.
Micotti, E.
Arosio, P.
Lascialfari, A.
Borsa, F.
Timco, G.
Winpenny, R. E. P.
Publication Year :: 2008
Abstract: We study the magnetization and the spin dynamics of the Cr$_7$Ni ring-shaped magnetic cluster. Measurements of the magnetization at high pulsed fields and low temperature are compared to calculations and show that the spin Hamiltonian approach provides a good description of Cr$_7$Ni magnetic molecule. In addition, the phonon-induced relaxation dynamics of molecular observables has been investigated. By assuming the spin-phonon coupling to take place through the modulation of the local crystal fields, it is possible to evaluate the decay of fluctuations of two generic molecular observables. The nuclear spin-lattice relaxation rate $1/T_1$ directly probes such fluctuations, and allows to determine the magnetoelastic coupling strength.<br />Comment: 3 pages, 2 figures, submitted as a contributed article for the Jems conference in Dublin (September 14-19 2008)