Electrical properties of p-type β-FeSi2 single crystals grown from Ga and Zn solvents

The electrical properties of beta-FeSi2 single crystals grown from solutions were investigated by the Hall effect measurements. The crystals grown from Ga solvent (Ga-beta-FeSi2) and Zn solvent (Zn-beta-FeSi2) showed p-type conduction. The resistivities at RT of Ga-beta-FeSi2 and Zn-beta-FeSi2 were 0.02-0.03 Omega cm (Ga) and 0.4-2 Omega cm (Zn), respectively. The hole concentration and Hall mobility at RT were (1-2)x 10(19) cm(-3) and 14-16 cm(2)/V s for Ga-beta-FeSi2 and (2-4)x10(17) cm(-3) and 19-46 cm(2)/V s for Zn-beta-FeSi2. The temperature dependence of the hole concentration reveals that ionization energy EA is approximately 0.02 and 0.12 eV for Ga-beta-FeSi2 and Zn-beta-FeSi2, respectively. We also found the intrinsic conduction of beta-FeSi2 above 500 K. (C) 2004 Published by Elsevier B.V.