Temperature dependence and permanent magnet properties of Fe-Pt-Ti alloys

In the present work investigations were made on the temperature dependence and the effects of adding a small amount of titanium on the magnetic properties of the Fe-Pt magnet alloys. Especially, the alloy containing 60.5 at% iron, 39at% platinum and 0.5at% titanium shows the highest maximum energy product of 170 kJ.m
^-3
, a coercive force of 400 kA.m
^-1
and a residual flux density of 1.04 T when tempered at 848 K after water-quenching. The temperature dependence of the magnetic properties of Fe-Pt-Ti magnets were measured using a VSM. As result, the maximum energy product of 210 kJ. m
^-3
(26 MG-Oe) is obtained at 77 K. It has been concluded that the origin of the excellent permanent magnet properties of the Fe-Pt alloy are closely related to the existence of a constitutionally imperfect η, phase and the initial ordering which result in the pinning of magnetic domain walls.