Journal of Physics Condensed Matter · 1998 · 15 citations · 14 references
Natural SciencesMaterials SciencePhysicsCeramic MaterialsInorganic ChemistryMaterials PhysicsCrystal LatticeCurie TemperatureFerroelectric CeramicsFerroelectric MaterialsInorganic MaterialsX-ray CrystallographyHyperfine InteractionsLattice ConstantsNuclear Quadrupole CouplingNuclear Quadrupole MomentsPolycrystalline MaterialsPowder X-ray DiffractionQuadrupole InteractionRhombohedral Unit Cells
In this paper, the hyperfine quadrupole interaction at the Zr-Ti site of (PZT) polycrystalline samples is studied for the first time. Powders for x = 0, 0.1, 0.2, 0.4, 0.6, 0.8, 0.9 and 1 were prepared and characterized by XRD. The lattice constants and space groups were obtained as functions of Ti concentration. PAC analyses were done for ferroelectric PZT for x = 0.9 and 0.8 as a function of temperature, and for x = 0.6 at RT. Also antiferroelectric was analysed. Low-concentration nuclei were used as probes. In the ferroelectric and paraelectric phases of PZT compounds two sites were occupied by probes. For each site the quadrupole frequency, asymmetry and relative distribution width parameters were obtained as functions of temperature above and below the Curie temperature. For only one site was detected with a static quadrupole interaction below and a nuclear spin-relaxation process above it. Furthermore, the temperature dependence of the hyperfine parameters, the possible origin of both quadrupole interactions in PZT and the perturbation that characterizes the cubic phases of and compounds are discussed.
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The chain structure of BaTiO3 and KNbO3
R. Comès, M. Lambert, A. Guinier · Solid State Communications · 1968 · 633 citations