Fabrication and characterization of Langmuir–Blodgett films based on rare earth β-Diketonate complexes

Langmuir–Blodgett (LB) films of Eu(dpm) 3 (dpm=2,2,6,6-tetramethyl-3,5-heptanedionate) and Gd(dpm) 3 coexisting with arachidic acid (AA) (complexes: AA=1:2, in molar ratio) with different molar percentages were prepared. Luminescence enhancement of Gd(dpm) 3 on Eu(dpm) 3 in the mixed films was studied in detail. The mixed monolayers of Eu(dpm) 3/Gd(dpm) 3/AA with different molar proportions at air–water interface were studied by π–A isotherms behaviors. The mixed LB films were characterized by means of low angle X-ray diffraction (LAXRD), UV-visible absorption spectra and photo-induced emission spectra. The possible structure of its resulting LB film was proposed. The results of UV-visible absorption spectra indicated that the complexes of rare earth-β-diketonate were homogeneously transferred onto the substrates layer-by-layer. The results of luminescence spectra also indicated that Gd(dpm) 3 and Y(dpm) 3 had a luminescence enhancement effect on Eu(dpm) 3 in the mixed LB films, while Gd(dpm) 3 had a stronger luminescence enhancement effect.