LAYERED MPS3 (M = MN, CD) THIN-FILMS AS HOST MATRICES FOR NONLINEAR-OPTICAL MATERIAL PROCESSING

The possibility of processing MPS3 (M = Mn, Cd) layered materials as t hin films capable of intercalating nonlinear optical chomophores is in vestigated. Two different synthetic routes are presented. The first me thod (solution approach) involves the coprecipitation of transition-me tal ions Mn2+ with ligands (P2S64-) followed by casting on a glass sub strate. Such films have a composition similar to the high-temperature- synthesized MnPS3 phase but exhibit a much lower crystallinity. Howeve r, XRD patterns reveal a preferential orientation of the layers parall el to the support. The second process (solid-state approach) uses the ability of the MPS3 layered compounds to be exfoliated through the suc cessive intercalations of K+ and Li+ cations. The resulting compounds of formula M1-xPS3Li2x. nH(2)O (x = 0.18 for the manganese derivative and 0.16 for the cadmium derivative) readily form highly orientated th in films. Highly transparent thin films were obtained from the CdPS3 s tarting material. The lithium intercalate thin films were characterize d by thermogravimetric techniques, IR spectroscopy, and X-ray diffract ion. Their mechanical stability was found to be slightly better than t hat of the solution-approach-based thin films. The intercalation of a nonlinear optical chromophore -(dimethylamino)-alpha-styryl]-1-methylp yridinium) was performed in these thin layered films, which were found to be much more reactive that the parent bulk MPS3.