Patent ID: 7470334

Claim:
A magnetostrictive material: formed by compaction in a magnetic field and then sintering a mixture containing a material A that is represented by Expression 7: (Tb x Dy 1-x )T y Ty (where, x and y atom ratios wherein x and y are in ranges of 0.35 <x <0.50 and 1.50 <y <2.30, respectively), a material B that is represented by Expression 8: Dy t T 1-t (where, Dy include at least one of Tb and Ho, and t is an atom ratio in range of 0.37 <t <1.00) and that contains hydrogen in the amount from 7000 ppm to 22000 ppm, and a material C containing T, and wherein the magnetostrictive material comprises: RT w (where, R is at least one kind of rare earth metal, T is at least one kind of transition metal, and w is 1.50 ≦w ≦2.30); and a degree of orientation greater or equal to 2; wherein the degree of orientation is I ⁡ ( 222 ) ⁢ ( // ) ⁢ / ⁢ I ⁡ ( 311 ) ⁢ ( // ) I ⁡ ( 222 ) ⁢ ( ⊥ ) ⁢ / ⁢ I ⁡ ( 311 ) ⁢ ( ⊥ ) (where, each of the I (222) and I (311) represents an x-ray diffraction intensity on a (222) plane and a (311) plane, respectively, and (//) and (⊥) represent measurements taken on a plane parallel and on a plane vertical, respectively, to a magnetic field orientation in the compaction in the magnetic field).