Galvanomagnetic properties of Heusler alloys Co2FeZ (Z = Al, Si, Ga, Ge, In, Sn, Sb)

Resumo

The magnetization, Hall effect, and resistivity of Heusler alloys Co₂FeZ (where Z = Al, Si, Ga, Ge, In, Sn, and Sb are s- and p-elements) have been studied at T = 4.2 K in magnetic fields H ≤ 100 kOe. In strong fields (H > 20 kOe), magnetization can be described by the Stoner model. The normal R₀ and anomalous R_S Hall effect coefficients have been determined. The coefficient RS is positive for almost all the studied alloys and represents a “linearly quadratic” resistivity function incorporating linear and quadratic terms. The constant R₀ is negative for most alloys, and its absolute value is two or three orders of magnitude smaller than for R_S. The magnetoresistivity of the studied alloys does not exceed several percent and may be both positive and negative for different specimens.