Alloy containing rare earth element, production method thereof, magnetostrictive device, and magnetic refrigerant material

An RE-containing alloy, which is represented by the formula R(T1−xAx)13−y (wherein R represents at least one species selected from among La, Ce, Pr, Nd, Sm, Eu, Th, Dy, Ho, Tm, Yb, Gd, and Lu;

• T represents at least one species selected from among Fe, Co, Ni, Mn, Pt, and Pd;
• and A represents at least one species selected from among Al, As, Si, Ga, Ge, Mn, Sn, and Sb (0.05≦x≦0.2;
• and −1≦y≦1)), and which comprises an R-rich phase, having a relatively high rare earth metal (R) content, and an R-poor phase, having a relatively low rare earth metal (R) content, wherein the R-rich phase and the R-poor phase are dispersed at a phase spacing of 0.01 to 100 μm.

An RE-containing alloy, which is represented by the formula R(T1−xAx)13−y (wherein R represents at least one species selected from among La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Tm, Yb, Gd, and Lu;

• T represents at least one species selected from among Fe, Co, Ni, Mn, Pt, and Pd;
• and A represents at least one species selected from among Al, As, Si, Ga, Ge, Mn, Sn, and Sb (0.05≦x≦0.2;
• and −1≦y≦1)), wherein the alloy has an NaZn13 phase content of at least 90 vol. %.