Zero-field quantum tunneling relaxation of the molecular spin in Fe8 observed by 57Fe Mössbauer spectrometryE. Molins, M. Gich, J. Tejada, J. M. Grenèche and F. MaciàEPL, 108 4 (2014) 47004DOI: https://doi.org/10.1209/0295-5075/108/47004