Three electrochemical cells with blocking, semi-reversible and reversi
ble electrodes were studied to pattern the ion distribution in Cu+-dop
ed Na-beta ''-Al2O3, single-crystal films. Luminescence changes were o
bserved with Ag and AgNO3, aq./NaNO3 aq. electrodes in the charged cel
ls. This is explained by Na+-Ag+ ion replacement. A sharp boundary bet
ween the different colour luminescent regions was achieved in the nitr
ate aq. solution cell. (C) 1998 Elsevier Science B.V. All rights reser
ved.