Elastic and magnetoelastic properties of polycrystalline rare-earth-iron laves compounds

Ultrasonic-sound velocity measurements have been used in order to determine the elastic moduli of polycrystalline rare-earth-iron Laves compounds RFe2 (R=Ce, Er) and YFe2 between 4.2 and 300 K. The ΔE effect of these compounds was determined in external magnetic field up to 25 kOe. No saturation was reached at this field in DyFe2 and TbFe2. The anomalies in the elastic behavior of CeFe2 and HoFe2 were interpreted in terms of changes occurring in their magnetic structure. The results reveal the high sensitivity of the elastic constants to such changes.