Showing papers by "L. E. Cross published in 1987"
TL;DR: In this paper, a phenomenological thermodynamic theory of PbTiO3 was developed using a modified Devonshire form of the elastic Gibbs free energy, which provided a way of predicting the intrinsic single domain dielectric and piezoelectric properties, which have not been completely determined from experimental measurements.
Abstract: A phenomenological thermodynamic theory of PbTiO3 was developed using a modified Devonshire form of the elastic Gibbs free energy. The spontaneous strain as a function of temperature was determined from pure sol‐gel derived PbTiO3 powder and used with selected data from the literature to determine the coefficients of the energy function. The theoretical prediction of the phase stability, spontaneous polarization and strains, and dielectric and piezoelectric properties agree well with experimental data. This theory provides a way of predicting the intrinsic single domain dielectric and piezoelectric properties of PbTiO3, which have not been completely determined from experimental measurements.
437 citations
Journal Article•
TL;DR: In this paper, the BaTiO 3 was added to BaTiVo 3, which permet d'eviter la formation de phase pyrochlore dans les ceramiques de PZN.
Abstract: L'addition de BaTiO 3 permet d'eviter la formation de phase pyrochlore dans les ceramiques de PZN. On etudie la preparation, les relations de phases et les proprietes dielectriques de plusieurs compositions du systeme binaire PZN-BT
200 citations
TL;DR: Temperature-dependent measurements of the optic index of refraction, the birefringence, and the strain in the ferroelectric, tungsten-bronze crystal suggest the crystals appear to possess a local, randomly oriented (up or down), polarization.
Abstract: We report accurate temperature-dependent measurements of the optic index of refraction, the birefringence, and the strain in the ferroelectric, tungsten-bronze crystal ${\mathrm{Ba}}_{0.4}$${\mathrm{Sr}}_{0.6}$${\mathrm{Nb}}_{2}$${\mathrm{O}}_{6}$. This composition congruently melts, so large homogeneous high-quality crystals can be grown. From the experimental data, it appears that far above the ferroelectric phase transition temperature (${T}_{c}$\ensuremath{\approxeq}88 \ifmmode^\circ\else\textdegree\fi{}C), up to a temperature ${T}_{d}$ (\ensuremath{\approxeq}300 \ifmmode^\circ\else\textdegree\fi{}C), the crystals appear to possess a local, randomly oriented (up or down), polarization ${P}_{d}$. The values of ${T}_{d}$ obtained from the index and completely independent strain measurements are in very good agreement with each other, as are the values of ${P}_{d}$. Various aspects of our understanding of the polarization behavior and other effects in this ferroelectric system are discussed.
140 citations
Journal Article•
TL;DR: Damjanovic et al. as discussed by the authors proposed Damjanovic, D Penn State Univ,Mat Res Lab,University Pk,Pa 16802G6809Times Cited:75Cited References Count:17 Reference LC-ARTICLE-1987-001 Record created on 2006-08-21, modified on 2017-05-10
Abstract: Note: Damjanovic, D Penn State Univ,Mat Res Lab,University Pk,Pa 16802G6809Times Cited:75Cited References Count:17 Reference LC-ARTICLE-1987-001 Record created on 2006-08-21, modified on 2017-05-10
111 citations
TL;DR: In this article, phase relations and dielectric properties of ceramics in the PZN-BT-PT system are reported, and compositions with the perovskite structure, having high dielectrics constant and low temperature coefficient of capacitance, have been identified.
Abstract: The use of Pb(Zn1/3Nb2/3)O3 ceramics is restricted by the formation of a pyrochlore phase detrimental to both dielectric and piezoelectric properties. Recently it has been shown that a 6 mol% addition of BaTiO3 to PZN suppresses the formation of pyrochlore phase. Phase relations and dielectric properties of ceramics in the PZN-BT-PT system are reported here. Compositions with the perovskite structure, having high dielectric constant and low temperature coefficient of capacitance, have been identified.
110 citations
TL;DR: In this paper, the dielectric, piezoelectric and pyroelectric properties of tungsten bronze single crystals in the Pb1-xBaxNb2O6 system were determined.
Abstract: Tungsten bronze single crystals in the Pb1-xBaxNb2O6 system were grown from a melt using the Czochralski technique. The dielectric, piezoelectric and pyroelectric properties were determined. The dielectric constant Ka and piezoelectric coefficient d15 showed a strong enhancement upon approaching the tetragonal: orthorhombic morphotropic phase boundary as predicted by thermodynamic phenomenology. It is clear that crystals with a composition in the tetragonal phase field near this boundary will be of major interest for various piezoelectric device applications.
38 citations
TL;DR: In this article, a sol-gel route in which Zn and Nb were prereacted to form Zn[Nb(OEt)6]2 in situ was described.
36 citations
4 citations
TL;DR: In this article, the authors measured the dielectric permittivity and loss tangent of four different calcium aluminate cements shear mixed with water and poly(vinyl alcohol) and cured at room temperature and laminates of SECAR 71 cement sintered at 1450°C.
Abstract: Dielectric permittivity and loss tangent were measured on: 1) pressed disks of four different calcium aluminate cements shear mixed with water and poly(vinyl alcohol) and cured at room temperature and 2) laminates of SECAR 71 cement sintered at 1450°C. Post resonance and perturbation methods were used for microwave frequency measurements. Far infrared dielectric response of the cements was determined by FTIR in the diffuse reflectance mode. The real and imaginary parts of the relative dielectric permittivity were obtained via a conventional Kramers-Kronig analysis.
1 citations
Journal Article•
TL;DR: In this article, the authors presented a method for the extraction of the structure of the Lipschitz constant of the Eq. 1.1 of the Wasserstein equation.
Abstract: Note: Penn State Univ,Mat Res Lab,University Pk,Pa 16802H1145Times Cited:0Cited References Count:0 Reference LC-ARTICLE-1987-002 Record created on 2006-08-21, modified on 2017-05-10