Perovskite lead-free dielectrics for energy storage applications

In response to the current environmental regulations against the use of lead in daily electronic devices, a number of investigations have been performed worldwide in search for alternative piezoelectric ceramics that can replace the market-dominating lead-based ones, representatively Pb(Zr
 x
 Ti1-x
 )O3 (PZT)-based solid solutions. Selected systems of potential importance such as chemically modified and/or crystallographically textured (K, Na)NbO3 and (Bi1/2Na1/2)TiO3-based solid solutions have been developed. Nevertheless, only few achievements have so far been introduced to the marketplace. A recent discovery has greatly extended our tool box for material design by furnishing (Bi1/2Na1/2)TiO3-based ceramics with a reversible phase transition between an ergodic relaxor state and a ferroelectric with the application of electric field. This paired the piezoelectric effect with a strain-generating phase transition and extended opportunities for actuator applications in a completely new manner. In this contribution, we will present the status and perspectives of this new class of actuator ceramics, aiming at covering a wide spectrum of topics, i.e., from fundamentals to practice.

Giant electric-field-induced strains in lead-free ceramics for actuator applications – status and perspective

We present a critical review that encompasses the fundamentals and state-of-the-art knowledge of barium titanate-based piezoelectrics. First, the essential crystallography, thermodynamic relations, and concepts necessary to understand piezoelectricity and ferroelectricity in barium titanate are discussed. Strategies to optimize piezoelectric properties through microstructure control and chemical modification are also introduced. Thereafter, we systematically review the synthesis, microstructure, and phase diagrams of barium titanate-based piezoelectrics and provide a detailed compilation of their functional and mechanical properties. The most salient materials treated include the (Ba,Ca)(Zr,Ti)O3, (Ba,Ca)(Sn,Ti)O3, and (Ba,Ca)(Hf,Ti)O3 solid solution systems. The technological relevance of barium titanate-based piezoelectrics is also discussed and some potential market indicators are outlined. Finally, perspectives on productive lines of future research and promising areas for the applications of these ma...

BaTiO3-based piezoelectrics: Fundamentals, current status, and perspectives

Recent development in lead-free perovskite piezoelectric bulk materials

Transparent ceramics: Processing, materials and applications

Highly transparent ceramics of La-doped 0.75Pb(Mg 1/3 Nb 2/3 ) O 3 -0.25PbTiO 3 were fabricated by a two-stage sintering method from conventional raw materials. The ceramics exhibited a transparency as high as 65% for the infrared wavelength. Large quadratic electro-optic coefficient of 66 x 10 -16 (m/v) 2 was obtained, which was the highest value reported so far in Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 ceramics. The ferroelectric phase inducing the threshold electric field E th and the domain structure of the transparent ceramics were studied.

Large Electro-Optic Effect in La-Doped 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 Transparent Ceramic by Two-Stage Sintering

Ferroelectric properties of Li-doped BaTiO3 ceramics

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O3 lead-free ceramics

Electrical properties of neodymium doped CaBi4Ti4O15 ceramics

Transparent ceramics of La-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) x/75/25 are prepared, and the ferroelectric domains, dielectric, and ferroelectric properties of x/75/25 are investigated. A double hysteresis loop and small fingerprint domains with uniform distribution observed for 3/75/25 indicate an intermediate ferroelectric state. The dielectric behavior under dc bias and the evolution of the hysteresis loop with increasing electric field for 3/75/25 indicate an electric field-induced phase transition, and it is proposed that the unstable intermediate ferroelectric state which would experience obvious field-induced phase transition is the origin of the giant electro-optic Kerr effect observed in La-doped PMN-PT 3/75/25.

Jiangtao Zeng

Papers

Large Electro-Optic Effect in La-Doped 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 Transparent Ceramic by Two-Stage Sintering

Ferroelectric properties of Li-doped BaTiO3 ceramics

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O3 lead-free ceramics

Electrical properties of neodymium doped CaBi4Ti4O15 ceramics

Origin of the giant electro-optic Kerr effect in La-doped 75PMN-25PT transparent ceramics