The temperature dependence of the magnetisation and of the elastic constant
s of CoMn single crystals were measured by SQUID-magnetometry and by ultras
onic pulse echo technique. The magnetisation exhibits a T-1/2-dependence an
d the cubic elastic constants show deviations from the quasiharmonic behavi
our in the vicinity of the superparamagnetic transition which is explained
by a coupling between strain and magnetisation. (C) 1999 Elsevier Science B
.V. All rights reserved.