Two crystal growth methods, Czochralski and floating zone, were applied for verifying the phase M solid-solution having superstructure along the e-axis of LiNbO3. In the crystals obtained by two different crystal growth methods, the common features of microstructure were observed such as the combination of the superstructure along the c-axis of LiNbO3 sub-cell and the self-organized regular array of the Li2TiO3 rod-precipitates perpendicular to the layer of the superstructure. Since a certain relationship of crystallographic orientation between the LiNbO3 and Li2TiO3 phase is retained, it was assumed that the formation of the micron order rod precipitates were derived from the interfacial energetic anisotropy of the superstructure of phase M. (C) 2003 Elsevier B.V. All rights reserved.