Magnetoelastic anomalies in CeNiSn

In this report, we present ultrasonic data of a CeNiSn single crystal with metallic low-temperature resistivity. The thermal variations of the elastic constants at high temperatures can be described by a two-band model using the deformation potential coupling approach. At very low temperatures, we observe a minimum in the field dependence of c11 and c33 accompanied by a maximum in the ultrasonic absorption. This may be a hint for a metamagnetic-like transition which is a frequent phenomenon in magnetically non-ordered heavy-fermion compounds. (orig.)