In situ x-ray diffraction studies were performed on the PLSnZT antiferroelectric–ferroelectric phase switching ceramic and polycrystalline powder. The crystallography of both the antiferroelectic and electric-field-induced ferroelectric phases were determined for the approximate composition of Pb0.98La0.02(Zr0.55Sn0.33Ti0.12)0.995O3. A preferred antiferroelectric domain structure has been identified and possible mechanisms responsible for the domain structure are presented. A single tetragonal phase has been identified for the room temperature zero-field antiferroelectric material with unit cell dimensions a=4.107 Å and c=4.081 Å. An electric field-induced structure developing at the antiferroelectric–ferroelectric switching field has also been observed and determined to be of rhombohedral symmetry with a=4.105 Å and θ=89.85° indicating a volume increase of 0.49% for the tetragonal–rhombohedral transition.

Neutron powder diffraction measurements and a constitutive model were used to determine the bulk longitudinal and transverse electrostrictive coefficients (Qijkl) for polycrystalline samples of the subject material. Effective single-crystal Qijkl were calculated from the powder neutron diffraction data. The resulting values of the three independent Qijkl, as determined from the cubic symmetry of the underlying lattice, are Q3333=2.1×10−2 m4/C2, Q3322=−0.87×10−2 m4/C2, and Q3232=1.2×10−2 m4/C2. Using these effective single-crystal values, a random ensemble average was used to predict the electromechanical performance of the polycrystalline material. Predicted values of bulk Q3333=1.86×10−2 m4/C2 and Q3322=−0.78×10−2 m4/C2 are 89% and 87%, respectively, of the effective single-crystal values for Q3333 and Q3322, while measured values of polycrystalline specimens are only ∼70% of the single-crystal values.

Superconducting Y1Ba2Cu3O7−δ thin films have been fabricated in situ by on-axis rf reactive magnetron sputtering from a single stoichiometric 1-2-3 target. By using high total sputtering pressures (≳400 mTorr) and low oxygen pressures (≤10 mTorr), negative ion resputtering is almost eliminated and high quality oriented films on (100)MgO are realized with excellent reproducibility. Such films display zero resistance Tc’s as high as 88 K with transition widths ΔTc (90%–10%) of about 2 K, residual resistivity ratios R(300 K)/R(100 K) of 2.5, and critical current densities greater than 106 A/cm2 at 14 K.

Intrinsic and coupling-induced elastic nonlinearity of lanthanum-doped lead magnesium niobate-lead titanate electrostrictive ceramic