This  article was jointly written  by NM2-Lab and  the group led by Prof. Alessandro Lascialfari at Pavia University , Italy , highlights the investigation of spin dynamics in magnetic hollow nanoparticles using proton nuclear magnetic resonance dispersion (¹H-NMRD). For the first time, a high-frequency component in the longitudinal relaxation rate was observed and attributed to surface spin dynamics. A two-population model (surface and core spins) was used to analyze the data, allowing the estimation of key parameters such as the hyperfine coupling constant and spin-spin correlation frequencies. Notably, the surface spin correlation frequency was found to be over 1 order of magnitude higher than that of the core. These findings enhance the understanding of spin behavior in nanoscale magnetic systems.

Unravelling the Surface Local Spin Dynamics in Magnetic Nanoparticles by Means of NMR Relaxometry. Physical Review Letters (2025). M. Basini, M. Mariani, Q. L. Vuong, Y. Gossuin, S. Slimani, G. Singh, D. Peddis, and A. Lascialfari. 
DOI: 10.1103/PhysRevLett.134.216703