Spontaneous magnetoimpedance in the Heusler compounds Pd2MnSn and Pd2MnSb near the Curie temperature

We report on magnetoimpedance (MI) measurements in the ferromagnetic Heusler compounds Pd2MnSn and Pd2MnSb in temperature ranges encompassing their Curie temperatures. In the ordered phase, spontaneous contributions to both the real and imaginary parts of the MI are identified below Tc in experiments performed at zero applied field. Large variations of the MI are also observed when a static magnetic field is applied parallel to the current orientation.