Reaction of Terfenol-D melts with SiO2 crucibles

The interaction between Terfenol-D (TbxDy1−xFey (0.27 ≤ x ≤ 0.30, y ≤ 2)) melts and quartz crucibles has been studied. A rare earth silicide was formed next to a rare earth oxide on SiO2 substrate and a surface layer of rare earth oxide appeared on top of the silicide layer. The reaction was controlled by diffusion with an activation energy Ea = 1.59 eV. The effect of Si contamination on the magneto-elastic property was evaluated. Maximum mangnetostriction of Terfenol-D decreased by 300 ppm while Si addition increased up to 1.0 at.%.