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The influences of temperature and hydrostatic pressure on the dielectric constant (ɛr) and loss (tanδ) of PbLa(Zr,Sn,Ti)O3 antiferroelectric ceramics have been studied. Temperature-induced transition from tetragonal antiferroelectric phase to cubic paraelectric phase and low-temperature frequency dispersion are observed. The dielectric behavior as a function of temperature was determined by XRD measurement. It has been found from experimental results that the ferroelectric–antiferroelectric phase transition temperature decreased and antiferroelectric–paraelectric phase transition temperature increased with increasing pressure.

Bi-based ceramics with pyrochlore structure exhibit interesting dielectric properties such as high dielectric constant and small dielectric loss at high frequency and low firing temperature. Structure and dielectric properties of non-stoichiometric ceramics Bi1.5−x ZnNb1.5O7−1.5x (with x = −0.25∼0.6) were investigated. The compounds departured from stoichiomeric compositions lead to structural parameters change. The second phase appeared when x ≥ 0.4. The lattice parameters of cubic pyrochlore Bi1.5−x ZnNb1.5O7 and grain size decreased as x increased. The experimental results show that dielectric constant decrease with increasing of the x value. The dielectric relaxation and defect resulting from non-stoichiometric ceramics Bi1.5−x ZnNb1.5O7−1.5x were discussed.

LaNiO3 (LNO) thin films were prepared on Si (100) wafer by MOD method. Pb(Zr, Ti)O3 ferroelectric thin films and their compositionally graded thin films were prepared on LNO/Si (100) substrates by a modified sol–gel method. The composition depth profile of a graded film was determined by using a combination of Auger electron spectroscopy and Ar ion etching. The results confirmed that the processing method produces graded composition change. XRD analysis showed that the graded thin film possessed a composite structure of tetragonal and rhombohedral. The dielectric constant of the graded thin films was higher than that of each thin film unit, but the loss tangent was near to each other at 10 kHz. The temperature characteristics of the dielectric constant of the graded thin films at different frequencies showed three peaks and ferroelectric relaxor feature to some extent. Hysteresis loops showed that graded thin film had higher remanent polarization, smaller coercive field than each thin film unit. The pyroelectric coefficient of the graded thin films increased gradually with temperature, and was higher than that of each thin film unit.

The Ba(Zr0.35Ti0.65)O3 (BZT) thin films were deposited via sol-gel process on LaNiO3-coated silicon substrates. XRD showed that the crystallinity of BZT film grown on LaNiO3 coated silicon substrates is better than that of BZT film grown on Pt. Both films showed perovskite phase and polycrystalline structure. The temperature dependent dielectric measurements revealed that the thin films had the relaxor behavior and diffuse phase transition characteristics. The capacitor tuning was about 44% for each BZT film grown on LaNiO3/Pt and Pt electrodes at 1 MHz. Especially, the values of dielectric loss at 1 MHz ranged from ∼0.02 to 0.009 in the bias range of 0 to 514 kV/cm, respectively. The leakage currents density of thin films grown on LaNiO3/Pt and Pt electrodes at 300 kV/cm was about 8.5 × 10−7 and 1.1 × 10−5 A/cm2, respectively. This work demonstrates a potential use of BZT films for application in tunable microwave devices.

PbTiO3 glass-ceramics were produced by a sol-gel process. DTA and X-ray diffraction analysis provided information about the structural transformations and crystallization temperature. The range of crystallization temperature of PbTiO3 is larger than that of PbTiO3 glass-ceramics. By increasing the glass composition, the crystallization temperature was increased. The phase transformation of PbTiO3 from the cubic to the tetragonal phase depends on the crystal size caused by the different heat treatment temperatures. The dielectric measurements in high frequency range (> 107Hz) exhibited evidence of a relaxation phenomena near 850 MHz. With increasing glass composition, the position of the relaxation frequency was increased. The temperature dependence of the dielectric constant of PbTiO3 and PbTiO3 glass-ceramics has an obvious discrepancy. The dielectric constant of PbTiO3 glass-ceramics shows the characteristic dispersion at the Curie point. It indicated that the glass ceramic sample has a stronger tendency for a diffuse phase transition.