Dielectric properties of single crystals of Pb(zr,til - x) O3 solid solutions (x∼0.5)

The dielectric constants and spontaneous polarisations of Pb(ZrxTi1-x)O3 single crystals (x = 0.4 ∼ 0.5) were measured. On the tetragonal side, the low frequency (1 kHz) free and high frequency (50 MHz) clamped dielectric constants along the a-axis, ∊T11, ∊S11, increase remarkably on approaching the tetragonal-trigonal morphotropic phase boundary. At this phase boundary, an increase of the low frequency free dielectric constant along the c-axis, εT33, is observed, but the high frequency clamped dielectric constant along the c-axis, ∊S33 is independent of the composition. The temperature dependence of the free and the clamped dielectric constants were measured for x = 0.5 and 0.51 single crystals. Above the Curie temperature, equality between ∊S33 and ∊11 was not observed. The temperature dependence of the spontaneous polarisation Ps(x = 0.4) was measured by the Sawyer-Tower method. The room temperature value of Ps is 50 ∼ 55 μC/cm2 for x = 0.4 ∼ 0.5 single crystals.