2009 Volume 50 Issue 3 Pages 483-486
The initial pressure shift of the Curie temperature Tc for the first-order transition, dTc⁄dP, for La(Fe0.88Si0.12)13 becomes small after hydrogen absorption. In addition, the hydrogen absorption reduces the ratio of the volume change at Tc to the magnetization squared at Tc, Δω(Tc)⁄M(Tc)F2, suggesting the decrease of the magnetoelastic coupling constant κCmv. On the other hand, dTc⁄dP is enhanced by the partial substitution of Ce for La in connection with the change of the band structure. Consequently, dTc⁄dP of La0.7Ce0.3(Fe0.88Si0.12)13Hy is larger than that of La(Fe0.88Si0.12)13Hy in a wide change of Tc.