Destruction of the short-range disorder due to erbium doping in Pb0.8La0.2TiO3films

We show the destruction of a displacement of Ti in the short-range structure by observing the disappearance of emission and Raman signals when the Er3+ concentration exceeds 7 mol% in sol-gel-derived Pb0.8La0.2TiO3 polycrystalline films. It is believed that there always exists disorder due to displacement of B ions in the skeleton of BO6 in perovskite ABO(3) materials. This disorder due to the displacement of Ti ions breaks the center of symmetry to activate emission of rare-earth ions such as Er3+ and Raman modes of perovskites. We found that the breaking of symmetry can be diminished by introducing more Er3+ ions. Copyright (C) 2009 John Wiley & Sons, Ltd.