Bi-Sb single crystals with a changed Sb composition to 18 at % have been grown by a modified Czochralski method with Sb feed. Gradient single crystals with a lattice parameter gradient of Deltac/(c) over bar/Deltaz = 0.972%/cm have been obtained. The effective distribution coefficients of Sb calculated according Ostrogorsky-Muller model for the gradient crystals growth were used. The influence of the growth parameters: the pulling rate and Sb feeding rate and the melt depth as a function of composition distribution in the bulk was studied. The concentration profiles, the lattice parameter c, the spacing crystalline planes Deltad and the dislocation density in the grown Bi-Sb gradient single crystals were measured. (C) 2003 Elsevier B.V. All rights reserved.