Large magnetostriction Fe-Pt-B amorphous alloys

The saturation magnetostriction has been measured at 77 K and room temperature for amorphous alloys series Fe80MxB20-xwith M=C, Si, Ge and Fe83-yMyB17with M=Ga Ge, Pt. It was found that the magnetostriction λsin Fe80GexB20-xincreases with increasing X in contrast to the decreased λsin Fe-C-B and Fe-Si-B alloys. The increase in y of the latter alloy series causes also the λsto increase at room temperature. The increment in λSof Fe-Pt-B alloys was large markedly. The Fe79Pt4B17alloy has λsof 46 × 10^-6at room temperature and λsof 63 × 10^-6at 77 K, being higher than values reported for Fe based alloys to date. A linear relation between λsand the magnetic moment was found to hold phenomenologically for Fe-M-B alloys with M=Ga, Ge and Pt having the increased λs.