Magnetocaloric effect and temperature coefficient of resistance of La[sub 2/3](Ca,Pb)[sub 1/3]MnO[sub 3].

The magnetocaloric effect of a La[sub 2/3](Ca,Pb)[sub 1/3]MnO[sub 3] single crystal was examined. From the measurements of isothermal magnetization and heat capacity around the Curie temperature, we have calculated the maximum isothermal magnetic entropy change as ∼7.5 J/kgK and the adiabatic temperature changes as ∼5.6 K, near room temperature for a 7 T magnetic field variation. Besides, the sharp drop of resistivity at the insulator-metal transition associated with the magnetic transition gives rise to a large temperature coefficient of resistance (TCR). For the La[sub 0.7]Ca[sub 0.3]MnO[sub 3] and La[sub 2/3](Ca,Pb)[sub 1/3]MnO[sub 3] single crystal, the peak of TCR is ∼50%/K at 218 K and ∼10%/K at 290 K, respectively. [ABSTRACT FROM AUTHOR]