| The excited state properties of the layered Ln[M(CN)2] 3 systems, (Ln = trivalent rare earth, La3+ and Eu 3+, M = Au, Ag, AgxAu1-x where x = 0.25, 0.50, 0.75, 0.90) have been studied. Additionally, dicyanoargentates(I) and dicyanoaurates(I) doped in alkali halides (LiCl, NaCl, RbCl and NaBr) along with K2Na[Ag(CN)2]3 have been examined.; Experiments on La[M(CN)2]3 systems were carried out to determine the existence of Ag(I)-Au(I) mixed metal interactions and consequently characterize these systems. Results have shown that mixed-metal interactions occur and that these mixed metal samples luminesce quite strongly at room temperature at an energy that is tunable by excitation wavelength. Tunability of the emission energy has also been achieved by varying the temperature and Ag/Au loading of the mixed metal complex. The emission energy of the mixed metal samples lie between those of the pure Au and Ag systems. The strong luminescence of the mixed metal systems at ambient temperatures is in stark contrast to the behavior of pure La[Au(CN)2]3 and La[Ag(CN) 2]3 samples.; The interesting properties exhibited by the pure gold and silver dicyanides and which also is exhibited by the mixed metal Ag(I)-Au(I) dicyanides, foremost of which is emission energy tunability, led to their use as donor systems with Eu(III) acceptor ions in energy transfer studies. Experimental results show that the mixed metal dicyanides with the higher silver loading have a better energy transfer efficiency than the pure Ag(CN)2 - and Au(CN)2- donors. The better energy transfer efficiency is due to the greater overlap between donor emission and acceptor excitation. Additionally, more acceptor states are available in the high silver loading mixed metal Eu(III) complexes.; Excimer/exciplex formation of *[Ag(CN)2-] n, *[Ag(CN)2-]n, and *[Ag xAu1-x(CN)2-] n units in an alkali halide host lattice are affected by the cation and anion sizes. Crystals containing Ag(CN)2- and Au(CN)2- exhibit optical memory. That is, when a crystal is irradiated at low-temperature, its luminescence properties differ from its luminescence before irradiation. The process is thermally reversible; heating the crystal restores it to its original state. Optical memory has also been found to occur in K2Na[Ag(CN)2] 3 and [Au(CN)2-]/NaCl systems. |
