Diffused morphotropic phase boundary results in high piezoelectricity and thermal stability
Diffused morphotropic phase boundary results in high piezoelectricity and thermal stability lead image
Improving solid solution ferroelectrics can lead to the development of new piezoelectric materials. Hoping to fully realize the potential of these materials, researchers are trying to expand their usage temperature, composition and field range while improving thermal stability.
Liu et al. studied relaxor-PbTiO3 crystals to better understand the impact of morphotropic phase boundary (MPB) on the stability and piezoelectricity of the material. With a series of synchrotron measurements, they were able to resolve the fine structure of the material and further characterize its properties.
“Achieving thermal stability is essential to evaluate the application direction of materials. It is especially important if we need to use the materials at various temperature conditions,” said author Gang Liu. “If a material has an improved thermal stability it will be more resistive to temperature variation, then the device can maintain the preferred performance.”
The authors found that the MPB in ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals was unexpectedly wide, covering 9% of the PbTiO3 system. Referred to as a “diffused” MPB, this resulted in high piezoelectricity and excellent thermal stability.
“We revealed that with appropriate materials-design, MPB can be broadened to a highly expansive composition-temperature region,” said Liu. “According to these results, we now understand when and why both high performance and great stability can be achieved simultaneously.”
Based on this research, the authors recommend that future piezoelectric materials design consider the width of MPB. They expect that other ferroelectric systems, such as lead-free ferroelectrics, may also benefit from diffused MPB.
Source: “Diffused morphotropic phase boundary in relaxor-PbTiO3 crystals: High piezoelectricity with improved thermal stability,” by Gang Liu, Lingping Kong, Qingyang Hu, and Shujun Zhang, Applied Physics Reviews (2020). The article can be accessed at https://doi.org/10.1063/5.0004324 .
