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

TL;DR

This study investigates the magnetization and spin dynamics of the Cr7Ni magnetic cluster, demonstrating that a spin Hamiltonian accurately models its behavior and exploring phonon-induced relaxation mechanisms.

Contribution

It provides a detailed analysis of Cr7Ni's magnetic properties and introduces a method to evaluate spin-phonon coupling via nuclear relaxation rates.

Findings

Spin Hamiltonian effectively describes Cr7Ni magnetization.

Phonon-induced relaxation dynamics characterized.

Magnetoelastic coupling strength estimated from relaxation data.

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.