Strong changes in electronic transport and magnetic properties of Co₂YSi Heusler alloys at Y-component variation

The Co₂ YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) Heusler alloys can manifest the properties of half-metallic ferromagnets. These compounds are promising materials for spintronics since almost 100 % spin polarization of charge carriers can be realized at room temperature. We measured the electroresistivity, magnetic and galvanomagnetic properties of the Co₂ YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) Heusler alloys from 4.2 K to 300 K and in magnetic fields up to 100 kOe. The type, concentration and mobility of charge carriers were estimated. The Y-component variation in the Co₂ YSi Heusler alloys is found to affect strongly the number of current carriers and alter the electronic band structure near the Fermi level E _F and, consequently, the electronic transport and magnetic properties of the Co₂ YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) Heusler alloys. (paper)