Nickel sulfides were prepared through a solvothermal process at 190degreesC by using NiCl2.6H(2)O and thiourea as reactants. XRD, XPS and SEM were used to study the phases, compositions and morphologies of the samples. it was found that through changing solvent and molar ratio of thiourea to NiCl2.6H(2)O, single-phase rhombohedral NiS (r-NiS) and hexagonal NiS (h-NiS) were obtained, NiS2 and Ni3S4 were also observed. r-NiS prepared in different solvents had different morphologies, such as rod-, sphere-, and petal-like. (C) 2002 Elsevier Science B.V. All rights reserved.