Dielectric Tunability Properties in (110)-Oriented Epitaxial 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 Thin Films Prepared by PLD Method

Epitaxial 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) thin films with single-crystal perovskite structure have been grown by pulsed laser deposition (PLD) on the (110) SrRuO3/SrTiO3 substrates. Temperature-dependent dielectric measurements show obvious characteristics of a diffused phase transition. Typical P-E hysteresis loops with a distinct ferroelectric imprint phenomenon are observed in these BZT-BCT thin films with a remnant polarization of 2.0 μC/cm2 and coercive field of 187 kV/cm. Small leakage currents (<1 × 10−6 A/cm2) are obtained in these thin films under an electrical field of 240 MV/m. These BZT-BCT thin films have shown large dielectric tunability values ranging from 75.8% to 85.7%, under a wide temperature range from 200 K to 330 K and a frequency range between 100 Hz and 100 kHz, which shows their good temperature and frequency stability. Such excellent dielectric tunability properties in these (110)-oriented BZT-BCT thin films promise their great potentials in practical phase shifter applications.

Niobate-based lead-free piezoceramics: a diffused phase transition boundary leading to temperature-insensitive high piezoelectric voltage coefficients

A large and thermally stable d33 was observed in dense and translucent KNN-based ceramics. Forming the R–O–T diffused phase transition is validated as a feasible way to realize the simultaneous enhancement of piezoelectricity and thermal stability.

Simultaneous enhancement of piezoelectricity and temperature stability in (K,Na)NbO3-based lead-free piezoceramics by incorporating perovskite zirconates

A new paradigm for the simultaneous enhancement of piezoelectric response and temperature stability by a compositionally modulated diffused phase transition.

The dielectric and ferroelectric properties of (Ba0.5Sr0.5)TiO3-doped (Bi0.5Na0.5)TiO3 lead-free ceramics

This work prepares (Ba[Formula: see text]Sr[Formula: see text])TiO3 (BST)-doped (Bi[Formula: see text]Na[Formula: see text])TiO3 (NBT) lead free ceramics through conventional solid reaction method and analyzes the doping effect of BST on phases, microstructure, dielectric and ferroelectric properties. The phase and structure of the NBT-BST ceramics were investigated through X-ray diffractometer (XRD) and Raman. The XRD results showed that BST has diffused into the NBT lattices to form a stable solid solution; while, Raman spectrum showed the bands at low frequency are different with that of pure NBT and divided into two ranges around 247[Formula: see text]cm[Formula: see text] and 303[Formula: see text]cm[Formula: see text]. Relative dense and homogeneous ceramic microstructures could be achieved, with the observation of a slight decrease in average grain size with the increase of BST doping content. The dielectric and ferroelectric properties were also investigated. The dielectric constant increases gradually with increasing the temperature to [Formula: see text], and then decrease. The temperature dependence property showed diffused phase transition near [Formula: see text]. The polarization-electric field ([Formula: see text]-[Formula: see text]) hysteresis loops of BST-doped NBT ceramics showed typical ferroelectric or relaxor nature. Both the [Formula: see text] and [Formula: see text] increased first, then decreased with respect to the increase of the BST content.