MÖSSBAUER STUDY OF THE TWO-DIMENSIONAL ANTIFERROMAGNET IN THE CRITICAL REGION : Rb2CoF4 : 57Fe AND Rb2Co0.95Mg0.05F4 : 57Fe A. Ito et M. HoriikeJ. Phys. Colloques, 40 C2 (1979) C2-323-C2-324DOI: https://doi.org/10.1051/jphyscol:19792113