Magnetostrictive properties of Tb<inf>.3</inf>Dy<inf>.7</inf>(Fe<inf>1-x</inf>Co<inf>x</inf>)<inf>1.9</inf>and Tb<inf>.3</inf>Dy<inf>.7</inf>(Fe<inf>1-x</inf>Ni<inf>x</inf>)<inf>1.9</inf>

Abstract

Measurements of Curie temperature, magnetic moment and magnetostriction were made on Tb .3 Dy .7 (Fe 1-x T x ) 1.9 where T = Co and Ni ( 0 \leq x \leq 1 for Co and 0 \leq x \leq .08 for Ni). Alloys were prepared using a float zone technique, from which it was possible to grow oriented [112] crystallite samples for 0 \leq x \leq .21 (T = Co). The Curie temperature peaked near x = .25 (T = Co) and decreased with increasing x (T = Ni). For both alloy systems the room temperature magnetic moment decreased with increasing x. An increase in the rare earth contribution of the magnetostriction of 12% is predicted for the Co substituted alloys with values of x near .25. This increase was not confirmed by the magnetostriction measurements. A decrease in magnetostriction with increasing x was observed for all x. This may be due to a defected platelet structure in the oriented alloys ( x \neq 0 ), or a negative contribution to the magnetostriction from the Fe 1-x Co x sublattice.