Anomalous structural behavior and antiferroelectricity in BiGdO₃: detailed temperature and high-pressure study

Area of Science:

• Solid State Physics
• Materials Science
• Crystallography

Background:

• Bismuth Gadolinium Oxide (BiGdO3) is a material with potential ferroelectric properties.
• Understanding its phase transitions under external stimuli is crucial for device applications.

Purpose of the Study:

• To comprehensively investigate the temperature and pressure-dependent properties of BiGdO3.
• To elucidate the nature of phase transitions in BiGdO3.

Main Methods:

• Dielectric constant and loss measurements
• Piezoelectric current and P-E loop analysis
• Raman scattering spectroscopy
• X-ray diffraction under high pressure

Main Results:

• Observed anomalies in dielectric properties at 290 K (Tr) and 720 K (Tc), indicating polarization reorientation and an antiferroelectric to paraelectric transition.
• Raman spectroscopy confirmed structural modifications and the antiferroelectric to paraelectric transition near Tc.
• High-pressure X-ray diffraction revealed a cubic to monoclinic structural transition at 10 GPa with significant volume collapse.
• Raman mode analysis corroborated the high-pressure structural transition and suggested a potential antiferroelectric to ferroelectric transition above 10 GPa.

Conclusions:

• BiGdO3 exhibits complex phase behavior under temperature and pressure.
• The material undergoes an antiferroelectric to paraelectric transition at 720 K and a structural transition at 10 GPa.
• Further investigation is warranted to confirm the pressure-induced antiferroelectric to ferroelectric transition.