Role of Fe substitution on the anomalous magnetocaloric and magnetoresistance behaviour in Tb(Ni1-xFex)2 compounds

We report the magnetic, magnetocaloric and magnetoresistance results obtained from Tb(Ni1-xFex)2 compounds with x = 0, 0.025 and 0.05. Fe substitution leads to an increase in the ordering temperature from 36 K for x = 0 to 124 K for x = 0.05. In contrast to the single sharp magnetocaloric effect (MCE) peak seen in TbNi2, the MCE peaks of the Fe-substituted compounds are quite broad. We attribute the anomalous MCE behaviour to the randomization of the Tb moments brought about by the Fe substitution. Magnetic and magnetoresistance results seem to corroborate this proposition. The present study also shows that the anomalous magnetocaloric and magnetoresistance behaviour seen in the present compounds is similar to that of Ho(Ni,Fe)2 compounds