57Fe AND 61Ni MÖSSBAUER EFFECT INVESTIGATIONS OF NICKEL FERRITE-ALUMINATES J.J. Bara, Z.M. Stadnik, G. Czjzek, J. Fink, V. Oestreich and H. Schmidt J. Phys. Colloques, 41 C1 (1980) C1-173-C1-174 DOI: 10.1051/jphyscol:1980148