Magnetic and Magnetoresistive Behavior of the Ferromagnetic Heavy Fermion YbNi2

Abstract

We present a study on the magnetic susceptibility χ(T ) and electrical resistance, as a function of temperature and magnetic field R(T, H), of the ferromagnetic heavy fermion YbNi 2 . The Xray diffraction analysis shows that the synthesized polycrystalline samples crystallizes in the cubic Laves phase structure C15, with a spatial group F d3m. The magnetic measurements indicate a ferromagnetic behavior with transition temperature at 9 K. The electrical resistance is metallic-like at high temperatures and no signature of Kondo effect was observed. In the ferromagnetic state, the electrical resistance can be justified by electron-magnon scattering considering the existence of an energy gap in the magnonic spectrum. The energy gap was determined for various applied magnetic fields. Magnetoresistance as a function of applied magnetic field, subtracted from the R(T, H) curves at several temperatures, is negative from 2 K until about 40 K for all applied magnetic fields. The negative magnetoresistance originates from the suppression of magnetic disorder by the magnetic field. 1 arXiv:1806.08881v1 [cond-mat.str-el]