Giant Hall effect in Ni-Mn-In Heusler alloys

We present experimental results on the giant Hall effect in the Heusler alloy Ni(50)Mn(50-x)In(x) with x=15.2. An unusual field dependence of the Hall resistivity (rho(H)) was observed in the vicinity of the martensitic phase transition, where rho(H) sharply increases up to rho(H) (15 kOe)=50 mu Omega cm. This value is comparable with the giant Hall resistivity in magnetic nanogranular alloys. Associated with rho(H), the Hall angle reaches a giant value of tan(-1) 0.5. An explanation of the giant Hall effect in Ni(50)Mn(50-x)In(x) Heusler alloys has been suggested.