INVESTIGATION OF MAGNETIC STRUCTURES AND PHASE TRANSITIONS IN NiS2 BY 61Ni-MÖSSBAUER SPECTROSCOPY G. CZJZEK, J. FINK, H. SCHMIDT, G. KRILL, F. GAUTIER, M.F. LAPIERRE and C. ROBERT J. Phys. Colloques, 35 C6 (1974) C6-621-C6-623 DOI: 10.1051/jphyscol:19746134