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 Pb_0.8La_0.2TiO₃ polycrystalline films. It is believed that there always exists disorder due to displacement of B ions in the skeleton of BO₆ in perovskite ABO₃ 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 © 2009 John Wiley & Sons, Ltd.