Achieving Temperature-Insensitive High Piezoelectricity by Reentrant Relaxor Transition

Area of Science:

• Materials Science
• Solid State Physics
• Ceramic Engineering

Background:

• Precision sensors and actuators require piezoelectric materials with high piezoelectric coefficients (d33).
• Achieving temperature-insensitive high d33 is challenging, especially for lead-free materials, due to sensitivity near ferroelectric transitions.

Purpose of the Study:

• To design a lead-free piezoelectric material with temperature-insensitive high piezoelectricity (d33).
• To investigate the mechanism behind the temperature-insensitive high d33 in the designed material.

Main Methods:

• Design of a lead-free Bi-doped (Ba,Ca)(Zr,Ti)TiO3 ceramic exhibiting a low-temperature reentrant relaxor transition.
• In situ microscopic observations and phase field simulations to analyze domain behavior.

Main Results:

• The designed ceramic shows a remarkable temperature-insensitive high d33 (≈350 pC N-1) from -40 to 85 °C.
• A reentrant relaxor state with orthorhombic nanodomains in a tetragonal matrix was identified.

Conclusions:

• The temperature-insensitive high d33 arises from the synergistic effect of reduced domain kinetic energy and increased orthorhombic nanodomain volume fraction.
• This work offers a new strategy for developing lead-free piezoelectric materials with stable high performance.