CHARACTERIZATION STUDY OF A PLATE OF THE MAGNETO-CALORIC MATERIAL La(Fe,Co,Si)_(13)

摘要

A sample of magnetocaloric material with nominal composition La(Fe_(0.851)Co_(0.066)Si_(0.083))_(13) is shown to present a ferromagnetic-to-paramagnetic transition with a Curie temperature of T_C = 278.7 K. Isothermal magnetization curves were used to determine the volumetric magnetic entropy change, △S_M(mJ/cm~3K). The values thus found are compared to those of Gd and found to be almost twice as large for a given field. Hysteresis curves and thermomagnetic data show that a slight thermal hysteresis of 2 K is present, while no magnetic hysteresis exists in this material. Therefore, we show that several of the disadvantages previously associated with NaZn_(13)-structured materials are not present in La(Fe,Co,Si)_(13) materials produced by powder metallurgy.