Anomalous acoustoelectric effect in La0.67Ca0.33MnO3 films - art. no. 146602

We have studied the acoustoelectric (AE) effect produced by surface acousti c waves (SAW) in a monolithic layered structure, composed of a piezodielect ric LiNbO3 substrate and a La0.67Ca0.33MnO3. film. The experiments unexpect edly revealed in the longitudinal AE effect an anomalous contribution, inva riant upon reversal of SAW propagation, which coexists with the ordinary (o dd in wave vector) effect. The anomalous effect dominates near the metal-in sulator transition, while the ordinary effect prevails at high and low temp eratures. We show that the anomalous effect is caused by,strong modulation of the film conductivity produced by the SAW elastic deformations.