High-pressure XRD study of β-Na_0.33V₂O₅

Abstract

We have investigated the pressure-dependent structural properties of the quasi-one-dimensional metal at room temperature by high-resolution angle-dispersive powder X-ray diffraction. According to our structural data, the crystal lattice of β-Na_0.33V₂O₅ remains monoclinic (space group C2/m) up to 20 GPa. The smallest compressibility is found along the conducting b-axis. We observe an anomaly in the pressure dependence of the lattice parameters and the volume of the unit cell in the range 12–15 GPa, in agreement with the pressure-dependent optical properties.

Keywords:

• low-dimensional transition-metal oxide
• crystal structure
• β-vanadium bronzes

Acknowledgements

We acknowledge the ESRF Grenoble for the provision of beamtime. Financial support by the Bayerische Forschungs-stiftung and the DFG (Emmy Noether-program, SFB 484) is gratefully acknowledged.