Synthesising and characterizing of the FePS3 layered compound and its intercalation with pyridinium ion (pyH(+)) were studied. Well-crystallized material of FePS3 was formed. Full insertion of pyH(+) was assured by X-ray diffraction (XRD) measurements. Two phases were produced due to intercalation, phase A (d = 12.1 Angstrom) and phase B (d = 9.7 Angstrom). There is a phase transformation of phase A to phase B. As a result of intercalation, there was a change in symmetry of the host lattice from C2/m to R-3m. The intercalated compounds, phase A and phase B, could be described by a trigonal unit cell and the lattice parameters a = b = 3.5026 Angstrom, and different values of the cell parameter c, which is lengthened due to increasing of the d-spacing (the interlayer space increases by 5.7 and 3.3 Angstrom of phase A and phase B, respectively), and gamma = 120degrees. Infrared spectra (IR) showed the presence of the strong peak of FePS3 at 570 cm(-1), which was splitted due to complete intercalation to two or three peaks. As a result of elemental analysis, there is a loss of Fe2+ cations due to the intercalation process, and so the intercalated guest species must be mainly present as pyH(+) to balance electrical charge (i.e. the intercalation of FePS3 with pyH(+) is a non-redox intercalation). (C) 2004 Elsevier B.V. All rights reserved.