Showing papers by "L. E. Cross published in 2007"
TL;DR: A nonspontaneous, high permittivity, "dielectrically soft" symmetry axis possessing large piezoelectric activity was found for predominantly ferroelectric tetragonal FT compositions in the relaxor lead magnesium niobate-ferroelectric lead titanate single crystal system as discussed by the authors.
Abstract: A nonspontaneous, high permittivity, “dielectrically soft” symmetry axis possessing large piezoelectric activity was found to exist for predominantly ferroelectric tetragonal FT compositions in the relaxor lead magnesium niobate–ferroelectric lead titanate, (1−x)Pb(Mg1∕3Nb2∕3)O3–(x)PbTiO3, single crystal system. The symmetry axis is not unique. It is a function of the lead titanate concentration x. It becomes the [011] for tetragonal compositions with x>0.35 and the [001] for rhombohedral compositions with 0.30⩽x⩽0.34. The two axial systems are degenerate for x∼0.35 and likely to converge at x∼0.29. Domain engineering for maximum piezoelectric response is easily accomplished for electric fields applied along this axis. The observations were confirmed by (1) isothermal resonance-antiresonance experiments on length extensional bars fabricated from multidomain (1−x)Pb(Mg1∕3Nb2∕3)O3–(x)PTiO3 single crystals and (2) numerical computation using Devonshire’s theory. The results are discussed in terms of recent f...
4 citations
TL;DR: In this article, the nonlinear dielectric response in Pb(Zn1∕3Nb2 ∕3)O3-PbTiO3 single crystals was investigated as a function of frequency between 30 and 250°C.
Abstract: The nonlinear dielectric response in [001] and [111] (1−x)Pb(Zn1∕3Nb2∕3)O3-xPbTiO3 (x=0045 and 008) single crystals was investigated as a function of frequency between 30 and 250 °C For comparison, a parallel study was carried out on a BaTiO3 single crystal Both second and third harmonic polarization components were detected in Pb(Zn1∕3Nb2∕3)O3-PbTiO3 and BaTiO3 single crystals, and were observed to go through maxima at the phase transition temperatures The third harmonic signal was nearly frequency independent for BaTiO3, but strongly dispersive in Pb(Zn1∕3Nb2∕3)O3-PbTiO3 The strong frequency dependence appears to be characteristic of some relaxor substructure of the domains
3 citations