The interaction between MgF2 and tris(8-hydroxy-quinoline) aluminum (Alq(3)) has been studied using high-resolution electron-energy-loss spectroscopy (HREELS). The reaction between MgF2 and Alq(3) occurred in the cases of both MgF2 deposited on Alq(3) and Alq(3) deposited on MgF2. The shift of the loss peak corresponding to the out-of-plane ring bend was observed similar to that for Mg deposited on Alq(3). The HREELS spectra indicated that Mg was produced from MgF2 deposited on Alq(3), and interacted with Al, O, and N in Alq(3). Analysis of the HREELS results suggested that Mg was not in the Alq(3) molecule plane. (C) 2003 Elsevier Science B.V. All rights reserved.