Preparation and some physical properties of (Bi1 − xSbx)2Se3single crystals

(Bi1 − xSbx)2Se3(x = 0.00−0.20) single crystals were prepared using a modified Bridgman method. Their homogeneity was studied by determining the antimony and bismuth content as well as the variations of the Seebeck coefficient in the directions perpendicular and parallel to the crystal axis. X-ray structure analysis revealed that the volume of the unit cell of the (Bi1 − xSbx)2Se3crystal lattice decreases with increasing value of x. Measurements of the electrical conductivity, Hall constant and Seebeck coefficient showed that incorporation of the antimony atoms into the Bi2Se3crystal lattice results in an increase of the free electron concentration for low antimony content, whereas the free electron concentration is suppressed in the range of the high antimony content. This effect is explained qualitatively on the basis of our ideas on the nature of the point defects in (Bi1 − xSbx)2Se3crystals.