Magnetization and spin dynamics of a Cr-based magnetic cluster:Cr7Ni

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 the 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.