The change of crystal and exchange parameters in the vicinity of TN in Cr2O3

A measurement of crystal parameters around T-N for Cr2O3 by neutron diffraction was performed. The dependence on crystal parameters of the magnetic interactions in Cr2O3 discussed in the literature was recalculated using a modified Oguchi theory and the known experimental data of the change of T-N with pressure. The controversy in sign in these experiments is discussed. The change across T-N of the largest exchange parameter Delta \ J(1)\ and the double sum Delta \ Y \ of the remaining parameters were estimated as well as their change under pressure. (C) 2000 Published by Elsevier Science S.A. All rights reserved.