Özet:
The influence of lead substitution on the magnetocaloric properties of La-0.7(Te1-xPbx)(0.3)MnO3 (0.0 <= x <= 0.3) manganites synthesized by solid-state reaction process was studied both by experimental and theoretical modeling. The X-ray diffraction patterns reveal that samples crystallize in the rhombohedral perovskite structure. Thermomagnetic measurements indicate that the magnetic transition temperature increases gradually from 238 to 262 K with increasing Pb amount in the structure. Maximum magnetic entropy changes (Delta S-M) are determined to be 7.16 for x = 0.0 and 4.76 J kg(-1) K-1 for x = 0.3. Relative cooling power (RCP) values of samples are ranging between 266.94 and 195.21 J kg(-1) at Delta H = 5 T. Due to relatively high Delta S-M and RCP values of the samples, they can be potential materials in magnetic refrigeration applications which work around room temperature.
