This review discusses recent advances in understanding origins of large piezoelectric properties in some ferroelectric materials. In particular, it addresses the role of polarization rotation and monoclinic phases. It is suggested that the polarization rotation is an old concept that was proposed more than 30 years ago to explain enhanced properties of Pb(Zr,Ti) 0 3 in the morphotropic phase boundary region. It is further demonstrated that in addition to polarization rotation, polarization extension can also lead to large electro-mechanical properties. In fact, the largest piezoelectric coefficient has been reported in KH 2 PO 4 , which exhibits structural instability involving polarization extension and no monoclinic phases. It is also shown that substantial theoretical and experimental evidence exists to show that the highest piezoelectric response is often not observed in monoclinic phases but in the phase transition regions where polarization either changes direction or appears from the nonpolar state. Finally, it is proposed that the concept of free energy instability, which emerged from phenomenological and first principle calculations, is the most general approach that can be used to consistently interpret many experimental observations and underlies many theoretical results on enhancement of piezoelectric properties.

Comments on Origins of Enhanced Piezoelectric Properties in Ferroelectrics

Competitive mechanism of temperature-dependent electrical properties in BiFeO3-BaTiO3 ferroelectrics controlled by domain evolution

Phase evolution and origin of the high piezoelectric properties in lead-free BiFeO3–BaTiO3 ceramics

Temperature-insensitive piezoelectric properties of lead-free BiFeO3–BaTiO3 ceramics with high Curie temperature

Barium titanate (BaTiO3) and Bismuth ferrite (BiFeO3) have been investigated for many years. Both of them have good electrical properties in the application of industries such as flexible displays,...

Muhammad Habib

Papers

Phase evolution and origin of the high piezoelectric properties in lead-free BiFeO3–BaTiO3 ceramics

Temperature-insensitive piezoelectric properties of lead-free BiFeO3–BaTiO3 ceramics with high Curie temperature

Enhanced piezoelectric performance of donor La3+-doped BiFeO3–BaTiO3 lead-free piezoceramics

Phase diagram for Bi-site La-doped BiFeO3BaTiO3 lead-free piezoelectric ceramics

Role of Bi chemical pressure on electrical properties of BiFeO3–BaTiO3–based ceramics