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, Gd, Tb, Dy, Dy, Ho, 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.