The Doniach diagram and hydrogenation of the ternary compounds CePdIn and CePdSn

The hydrogenation process of the antiferromagnetic compounds CePdIn and CePdSn has been studied. Investigation of the new hydrides CePdInH and CePdSnH by X-ray powder diffraction shows that they adopt the same crystal symmetry as the original intermetallic but the unit cell volume increases during the hydrogenation. Magnetization, electrical resistivity, thermoelectric power and Sn Mössbauer spectroscopy measurements reveal that CePdInH and CePdSnH order antiferromagnetically below TN = 3.0(2) K and 5.0(2) K respectively. Moreover, the physical properties of the hydrides are less influenced by the Kondo effect. The changes of Néel temperature involved by H-insertion are explained on the basis of the Doniach’s diagram considering the competition between Kondo and RKKY interactions.