Electrical properties of Co-doped β -FeSi2 crystals

Abstract

␤-FeSi 2 crystals were grown from high-purity starting materials by chemical vapor transport. The crystals were in situ n-type doped adding Co to the source material. Electrical properties have been investigated by temperature-dependent resistivity and Hall effect measurements. Above 100 K, we observed conventional conduction band transport. The Co doping was found to create a shallow donor level at E c -0.053 eV. Hall mobilities up to 50 cm 2 /Vs were observed. At lower temperatures defect band conduction dominates the electrical transport and negative magnetoresistance is observed. The main contribution to the Hall voltage observed at low temperatures arises from the anomalous Hall effect.

Solution growth of n-type - single crystals using Sn solvent

“…The values of our mobility were similar to that of typical n-type b-FeSi 2 single crystals grown by CVT [17,18].…”

“…[12] but lower than that of undoped b-FeSi 2 single crystals grown by the CVT method ð4221O cmÞ [16,17]. The resistivity increased with decreasing the temperature and shoulder-like sections were observed below about 120 K. A further decrease of temperature causes a much slower increase of r: This temperature dependence of r is also observed in n-type b-FeSi 2 grown by CVT [18].…”

“…Brehme et al gave a more detailed discussion of this problem assuming the existence of a defect band [18].…”

“…7(b). This allows us to derive the value of E D and N D : We calculated the parameters by using the values of g ¼ 2 and m à e ¼ 1:0 [18]. Results are given in Table 3.…”

Solution growth of n-type β-FeSi2 single crystals using Ni-doped Zn solvent

“…The mobilities of n-type crystals were 3-6 cm 2 /V s, which are approximately one order of magnitude lower than the value of p-type crystal. The values of our mobility were similar to typical values of n-type b-FeSi 2 single crystals grown by CVT and TGSG method [4,5,7]. Fig.…”