Transport properties of Cr-doped beta-FeSi2

The temperature dependence of the Hall coefficient in p-type Cr-doped beta -FeSi2 films and single crystals is analyzed within the framework of a simp le model of a semiconductor with two types of carriers of one sign. The res ult indicates the existence of an impurity band and makes it possible to de termine the gap between the main and impurity band formed by shallow accept or levels. The value of the activation energy of the deep accepters, the co ncentration of the shallow and deep acceptors as well as the concentration of the compensating donors are also calculated. Furthermore, the dominant s cattering mechanisms are determined. (C) 2001 Elsevier Science B.V. All rig hts reserved.