Hydrogen induced antiferromagnetism in CeNiSn studied by heat capacity and magnetocaloric effect

Abstract Hydrogenation of CeNiSn provokes a change of the ground state of cerium from Kondo insulator to antiferromagnetic ( CeNiSnH 1.0 ) or ferromagnetic ( CeNiSnH 1.8 ) behaviour. We report heat capacity measurements in CeNiSnH 1.0 performed in magnetic fields up to 90 kOe. The calculated magnetocaloric effect has a maximum at temperatures close to T N = 4.5 K . The values of the isothermal magnetic entropy ( Δ S m ) and the adiabatic temperature change ( Δ T ad ) are modest, and similar to those found in other Ce compounds. The field dependence of both, heat capacity and magnetocaloric effect clearly indicate the nature of the magnetic transition.