Phase transition on ferroelectric ceramics by photoacoustic detection

Phase transition on ferroelectric ceramics were detected by photoacoustic l aser technique which allows the measurement of the Curie temperature and fe rro-paraelectric transitions. The photoacoustic signal produced by low ener gy laser pulses using a piezoelectric transducer attached to the sample by a glass or quartz rod is shown. The developed technique requires nor signal amplification neither special preparation of the sample and have an excell ent signal to noise ratio. Ln order to validate this technique it was appli ed to the measurement of Curie temperature of the PbSmTiO3 and Pb(MgNb)TiO3 ceramics. These results were compared with those obtained by DTA, DMA and dielectric permittivity.