New type of ultrahigh piezoelectricity in hydrogen-bonded ferroelectrics

November 20, 2020

Prevalent piezoelectric materials like barium titanate (BaTiO3) and lead zirconate titanate (PZT) possess high piezoelectric coefficients 20-800 pC/N, which are also ferroelectric. The Curie temperature of those ferroelectrics are mostly far above room temperature, so the change of polarization ΔP upon a strain at room temperature is approximately the same as ΔP0 at 0K.

Recently, scientists at Huazhong University of Science and Technology and at the Nanjing University in China proposed a new possibility of inducing ultra-high piezoelectric coefficient, which will be theoretically infinitely large if the Curie temperature is right at the working temperature and sensitive to strain. Well-known ferroelectric perovskites like BaTiO3 or PZT are not such candidates due to their high Curie temperature that is insensitive to strain. However, many hydrogen-bonded ferroelectrics with Curie temperature ranging from 200 to 400K can be ideal candidates, which are also soft, flexible and lead-free. For examples, the measured Curie temperature of organic PhMDA and [H-55DMBP][Hia] were respectively 363 and 268K. For hydrogen bonds like O-H...O, each proton will be covalently bonded to only one side of O atom due to the saturation of covalent bond. The O-H bond is on the verge of breaking at the hopping transition state where the proton locates at the midpoint. Due to the brittle nature of covalent bond, if the O-H...O bonds are prolonged upon a tensile strain, the hopping barrier as well as Curie temperature may be greatly enhanced with a much larger transfer distance. Meanwhile their hydrogen-bonded network can be easily compressed or stretched due to low bulk modulus.

The authors have shown first-principles evidence combined with Monte Carlo simulation, that the proton-transfer barriers as well as the Curie temperature of some hydrogen-bonded ferroelectrics can be approximately doubled upon a tensile strain of as low as 2 %. Their Curie temperature can be tuned exactly to room-temperature by applying a fixed strain in one direction, and the systems will exhibit ultra-high piezoelectricity in another direction. The unprecedented piezoelectric coefficient of 2058 pC/N obtained in PhMDA is more than 3 times higher than PZT, and an order of magnitude higher than the highest value obtained in current lead-free piezoelectrics. This value is even underestimated and can be greatly enhanced upon smaller strain. Since this proposed principle for such piezoelectricity can be applied to most hydrogen-bonded ferroelectrics, the large number of organic or inorganic candidates should facilitate its experimental realizations and optimizations in future, which will be a breakthrough for the long-sought lead-free high-coefficient piezoelectrics. This mechanism may also clarify the previously reported drastic rise in piezoelectric coefficient for SbSI when approaching its Curie temperature.
See the article:
Yangyang Ren, Menghao Wu, Jun-Ming Liu
Ultra-High Piezoelectric Coefficients and Strain-Sensitive Curie Temperature in Hydrogen-Bonded Systems
Natl Sci Rev (2020)

Science China Press

Related Temperature Articles from Brightsurf:

History of temperature changes in the Universe revealed
How hot is the Universe today? How hot was it before?

A drop in temperature
In the nearly two centuries since German physician Carl Wunderlich established 98.6°F as the standard ''normal'' body temperature, it has been used by parents and doctors alike as the measure by which fevers -- and often the severity of illness -- have been assessed.

Kitchen temperature supercurrents from stacked 2D materials
A 'stack' of 2D materials could allow for supercurrents at ground-breakingly warm temperatures, easily achievable in the household kitchen.

Get diamonds, take temperature
Measuring the temperature of objects at a nanometer-scale has been a long challenge, especially in living biological samples, because of the lack of precise and reliable nanothermometers.

Chemical thermometers take temperature to the nanometric scale
Scientists from the Coordination Chemistry Laboratory and Laboratory for Analysis and Architecture of Systems, both of the CNRS, recently developed molecular films that can measure the operating temperature of electronic components on a nanometric scale.

How reliable are the reconstructions and models for past temperature changes?
Understanding of climate changes during the past millennia is crucial for the scientific attribution of the current warming and the accurate prediction of the future climate change.

New method measures temperature within 3D objects
University of Wisconsin-Madison engineers have made it possible to remotely determine the temperature beneath the surface of certain materials using a new technique they call depth thermography.

Who takes the temperature in our cells?
The conditions in the environment are subject to large fluctuations.

Taking the temperature of dark matter
Warm, cold, just right? Physicists at UC Davis are using gravitational lensing to take the temperature of dark matter, the mysterious substance that makes up about a quarter of our universe.

Thermal siphon effect: heat flows from low temperature to high temperature
In this work, researchers study (both thermal and electric) energy transport in physical networks that rewired from 2D regular lattices.

Read More: Temperature News and Temperature Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to