Chiang Mai Journal of Science

 In this study, the dielectric properties under the uniaxial stress of the unpoled ceramics are investigated. The (x) Pb(Mg_1/3Nb_2/3)O₃ - (1-x) Pb(Zr_0.52Ti_0.48)O₃ (when x = 0.0, 0.3, 0.5, 0.7 and 1.0) ceramic composites are perpared by a conventional mixed-oxide method. The experiment is carried out with the calibrated uniaxial compressometer under the stress level up to 5 MPa. The results show that the dielectric properties of the unpoled ceramics increase with increasing stress up to 1 MPa, and become relatively constant with the applied stress. This is believed to be a result of random orientation of the domains in unpoled ceramics. It is very of interest to find that these results for the unpoled ceramics are significantly different from those for the poled ceramics in which noticeable changes of the dielectric properties under the uniaxial stress are observed.