Photoacoustic experiments were carried out in two ceramic compounds to pres
ent a promising way to study relaxor materials. This technique has been sho
wn to have some advantages in the investigation of phase transitions in a v
ariety of materials. We use the temperature-dependent data of both dielectr
ic and photoacoustic responses from the ceramic compound Bi4-xRxTi3O12, wit
h R-x=Pr, x=0 and 1.6, to illustrate this work. We establish definitely tha
t Bi4Ti3O12 is a relaxor. (C) 2001 American Institute of Physics.