Mechanism for Improved Curie Temperature and Magnetic Entropy Change in Sm-Doped Fe 88 Zr 8 B 4 Amorphous Alloys.

In the present work, Fe 88 Zr 8-x Sm x B 4 (x = 2, 4) amorphous alloys (AAs) were successfully synthesized into the shape of 40-micrometer-thick ribbons and their magnetic properties were measured. The Fe 88 Zr 8-x Sm x B 4 (x = 2, 4) AAs exhibited a rather high maximum magnetic entropy change (-Δ S m peak ): ~3.53 J/(K × kg) near 317 K for x = 2 and ~3.79 J/(K × kg) near 348 K for x = 4 under 5 T. The effects of a Sm substitution for Zr on the Curie temperature ( T c ) and -Δ S m peak were studied and compared to those of Nd and Pr substitutions, for the purpose of revealing the mechanism involved in more detail.