Low field de susceptibility measurements have been made on an Fe3-xMnx
Si alloy with x = 1.14. The observed and calculated results show a dem
agnetising effect to be occuring in and around the ferromagnetic regim
e. This brings into question earlier assertions of spin-glass or micto
magnet like properties and the critical exponent estimates for these a
lloys because they lie within the region of significant demagnetisatio
n.