(NH4)2WTe2O8 at 5.09 GPa: a single-crystal study using synchrotron radiation

Area of Science:

• Solid-state chemistry
• Crystallography
• Materials science

Background:

• Diammonium [octaoxidoditellurato(IV)]tungstate, (NH(4))(2)WTe(2)O(8), is a polar crystal with potential applications in materials science.
• Understanding its structural behavior under pressure is crucial for predicting its properties and potential uses.

Purpose of the Study:

• To investigate the structural response of diammonium [octaoxidoditellurato(IV)]tungstate to high pressure.
• To determine if pressure induces any phase transitions in the crystal structure.

Main Methods:

• Single-crystal X-ray diffraction was employed to study the crystal structure.
• Experiments were conducted using a diamond-anvil cell at the HASYLAB synchrotron.
• Structural analysis was performed at pressures up to 7.16 GPa.

Main Results:

• No phase transition was observed in the crystal structure up to 7.16 GPa.
• A detailed structure determination at 5.09 GPa revealed a significant change.
• The coordination number of one tellurium atom decreased from four to three.

Conclusions:

• The polar crystal structure of diammonium [octaoxidoditellurato(IV)]tungstate is stable under high pressure up to 7.16 GPa.
• Pressure induces a change in the local coordination environment of tellurium atoms.
• This finding provides insights into the pressure-dependent properties of tungstate-tellurate compounds.