Mg2Si and Ca2Si bulk crystals were grown, and their structural and morphological properties have been investigated. The Mg2Si crystals without any cracks or voids were grown by an interdiffusion process between the deposited Mg atoms and Si bulk crystals in a vacuum. Single phase Ca2Si bulk crystals were also grown by the interdiffusion process using Ca and Mg2Si crystals. The structural properties and the growth evolution of the silicides are discussed in comparison with those of the silicide layers. (c) 2004 Elsevier B.V. All rights reserved.