Magnetotransport properties and magnetocaloric effect in La0.67Ca0.33Mn1−xTMxO3 (TM=Cu, Zn) perovskite manganites

The magnetic and transport properties of the perovskites La0.67Ca0.33Mn1-xTMxO3 were found to be sufficiently changed with the substitution of Mn-sites by other 3d transition-metal cations (TM=Cu,Zn; x=0.15). The values of TC, TM−I, and TCMR were surveyed when Mn was replaced by Cu and Zn. The magnetic field induced resistivity and magnetic entropy change of these samples showed abrupt changes near TC (194.2 and 201.5 K for Cu and Zn-doped case respectively) and attained the highest values among the doped cases (up to 20% Cu). The maximum values (obtained at H=4 kOe) of magnetoresistance ratio (CMR) were 27.8%, and 24.5% and of magnetic entropy change (−ΔSM) were 3.9 and 3.2 J/kg K for Cu and Zn-doped, respectively.

► Highest CMR and MCE found among Cu and Zn-doped La0.67Ca0.33MnO3 compounds (up to 20% doping).
► Second-order magnetic phase transition with monotonous change of TC according to doping content.
► No abrupt change of electrical and magnetic properties of doped compounds at 15% doping.