Giant magnetostriction materials from cryogenic temperatures to 250 C

摘要

Abstract: Huge magnetoelastic interactions in the rare earths Tb, Dy, and Sm provide the basis of a technically important class of magnetostrictive materials with saturation strains, 10$+$MIN@3$/ $LS $Delta$EL@/$EL $LS 10$+$MIN@2$/. Rare earth elements, oxides, intermetallic compounds, and rapidly quenched amorphous metals all exhibit large magnetostrictions. Of particular importance here are the binary hexagonal Tb$-x$/Dy$- 1$MIN@x$/ alloys, which produce extremely high magnetostrictions at cryogenic temperatures, and the pseudobinary cubic Tb$-x$/Dy$-1$MIN@x$/Fe$-2$/ compounds, which exhibit huge strains at room temperature and above. For the highly magnetostrictive room temperature materials, specific features which dominate the magnetostrictive behavior are: (1) large magnetic moments ($APEQ@1 T), (2) large magnetostriction anisotropy, $lambda$-111$/ $VGRT $lambda$-100$/, and (3) changes in the magnetic easy axes from $LS@100$GRT (low magnetostrictive) to $LS@111$GRT (giant magnetostrictive) with temperature. Magnetostrictions $GRT 10$+$MIN@3$/ are found as high as 150$DGR@C in Tb$-.27$/Dy$-.73$/Fe$-2$/ and 250$DGR@C in TbFe$-2$/. !12