MÖSSBAUER SPECTROSCOPY OF Ni-FERRITE AND NON-STOICHIOMETRIC Ni-Zn FERRITES R. VALENZUELA, J. A. GARCÍA, S. ABURTO, M. L. MARQUINA et M. JIMÉMEZ J. Phys. Colloques, 38 C1 (1977) C1-139-C1-140 DOI: 10.1051/jphyscol:1977127