Tb5Si3 single crystals were grown by a vertical floating zone method with radiation heating at a zone traveling rate of 3 mm/h. The compound exhibits congruent melting behavior at a temperature of about 1785 degrees C. The crystal is nearly stoichiometric as proved by chemical analysis and exhibits a hexagonal Mn5Si3-type structure with lattice parameters a=0.8469 nm and c=0.6354 nm. Platelet-like Tb5Si4 precipitates contained in the crystal matrix proved that the Tb5Si3 compound possesses a finite homogeneity range. The fraction of precipitates has been diminished by crystal growth with slightly Si depleted feed rod compositions. Single crystalline samples exhibit magnetic ordering below a temperature T-N=69 K and a magnetic easy axis [0 1 0] in the basis plane of the hexagonal unit cell. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.