Long- and short-range structure studies of KBT-KBZ solid-solutions using synchrotron radiation

Area of Science:

• Materials Science
• Solid-state Chemistry
• Crystallography

Background:

• Relaxor ferroelectrics like K(0.5)Bi(0.5)TiO(3) (KBT) exhibit unique dielectric properties.
• Understanding the structural basis of ferroelectricity is crucial for designing advanced materials.
• Solid solutions offer a pathway to tune material properties by compositional control.

Purpose of the Study:

• To investigate the structural evolution and ferroelectric behavior of K(0.5)Bi(0.5)Ti1-xZrxO(3) solid solutions.
• To determine the effect of Zr doping on the local and long-range structure of KBT.
• To elucidate the relationship between structural changes and ferroelectric properties.

Main Methods:

• Synthesis of K(0.5)Bi(0.5)Ti1-xZrxO(3) solid solutions.
• High-resolution synchrotron X-ray powder diffraction for average structure analysis.
• X-ray absorption near edge structure (XANES) spectroscopy for local structural characterization.

Main Results:

• A pseudocubic tetragonal phase was observed across the entire solid-solution series.
• KBT exhibits a broad ferroelectric transition around 683 K.
• Zr doping minimally impacts Ti off-centering but leads to reduced polar domains and ferroelectric response.

Conclusions:

• Zr doping in KBT does not significantly alter Ti off-centering but influences local coordination environments.
• The dilution effect of Zr doping reduces polar domain size, leading to a weaker ferroelectric response.
• The study provides insights into structure-property relationships in KBT-KBZ solid solutions.