Abrupt crossover between thermally activated relaxation and quantum tunneling in a molecular magnetK. M. Mertes, Y. Zhong, M. P. Sarachik, Y. Paltiel, H. Shtrikman, E. Zeldov, E. Rumberger, D. N. Hendrickson and G. ChristouEurophys. Lett., 55 6 (2001) 874-879DOI: https://doi.org/10.1209/epl/i2001-00363-0