title: Effect of magnetic field on the crystalline structure of magnetostrictive TbFe2 alloy solidified unidirectionally in microgravity.
abstract: We performed unidirectional solidification experiments on TbFe(2) alloy in a static magnetic field in microgravity of 10(-4) g for 10 sec obtained by a 490 m free fall of the Japan microgravity center (JAMIC). When the magnetic field strength was increased from zero to 4.5 x 10(-2) T during unidirectional solidification in microgravity, a [1 1 1] crystallographic alignment dominated, and the maximum magnetostriction constant increased from 1,000 ppm to 4,000 ppm. For unidirectional solidification in normal gravity, the maximum magnetostriction constant remained at 2,000 ppm with increasing magnetic field. The columnar structure grows and orients along the magnetic field. TbFe(2) crystals grow in microgravity predominantly in the same direction as the magnetic field.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, Tsukuba, Ibaraki 305-8565, Japan. okutani-takeshi@aist.go.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okutani
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nakata
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nagai
mesh_terms: D000497:Alloys; D003460:Crystallization; D003461:Crystallography / Q000379:methods*; D006112:Gravitation; D007501:Iron / Q000737:chemistry*; D046911:Macromolecular Substances; D008280:Magnetics; D010825:Physics / Q000379:methods; D013026:Space Flight; D013696:Temperature; D013725:Terbium / Q000737:chemistry*; D013997:Time Factors; D014893:Weightlessness; D018474:Weightlessness Simulation
chemical_list: D000497:Alloys; D046911:Macromolecular Substances; D013725:Terbium; D007501:Iron