doi:10.1209/0295-5075/108/47004

57Fe Mössbauer spectrometry has been performed on oriented crystalline 57Fe enriched samples of Fe8 at 12 K under different applied magnetic fields. Fe8 has an S = 10 ground state and exhibits magnetic anisotropy with a barrier height of about 27 K. Under longitudinal magnetic fields, the energies of the spin levels coincide at steps of about 2.25 kOe, where tunneling relaxation occurs. We present here an experiment specially designed to observe quantum tunneling of molecular spin at zero field through Mössbauer. We report observation of quantum tunneling at temperatures of 12 K.