Enhanced magnetic anisotropy and high hole mobility in magnetic semiconductor Ga1-x-y Fe x Ni y Sb

Abstract (Ga,Fe)Sb is a promising magnetic semiconductor (MS) for spintronic applications because its Curie temperature ( T C ) is above 300 K when the Fe concentration is higher than 20%. However, the anisotropy constant K u of (Ga,Fe)Sb is below 7.6 × 10 3 erg/cm 3 when Fe concentration is lower than 30%, which is one order of magnitude lower than that of (Ga,Mn)As. To address this issue, we grew Ga 1- x - y Fe x Ni y Sb films with almost the same x (≈24%) and different y to characterize their magnetic and electrical transport properties. We found that the magnetic anisotropy of Ga 0.76- y Fe 0.24 Ni y Sb can be enhanced by increasing y , in which K u is negligible at y = 1.7% but increases to 3.8 × 10 5 erg/cm 3 at y = 6.1% ( T C = 354 K). In addition, the hole mobility ( µ ) of Ga 1- x - y Fe x Ni y Sb reaches 31.3 cm 2 /(V∙s) at x = 23.7%, y = 1.7% ( T C = 319 K), which is much higher than the mobility of Ga 1- x Fe x Sb at x = 25.2% ( µ = 6.2 cm 2 /(V∙s)). Our results provide useful information for enhancing the magnetic anisotropy and hole mobility of (Ga,Fe)Sb by using Ni co-doping.