Unusual Low-Temperature Phase in VO${}_2$ Nanoparticles

Abstract

We present a systematic investigation of the crystal and electronic structure and the magnetic properties above and below the metal-insulator transition of ball-milled VO${}_2$ nanoparticles and VO${}_2$ microparticles. For this research, we performed a Rietveld analysis of synchrotron radiation x-ray diffraction data, O $K$ x-ray absorption spectroscopy, V $L_3$ resonant inelastic x-ray scattering, and magnetic susceptibility measurements. This study reveals an unusual low-temperature phase that involves the formation of an elongated and less-tilted V-V pair, a narrowed energy gap, and an induced paramagnetic contribution from the nanoparticles. We show that the change in the crystal structure is consistent with the change in the electronic states around the Fermi level, which leads us to suggest that the Peierls mechanism contributes to the energy splitting of the $a_{1g}$ state. Furthermore, we find that the high-temperature rutile structure of the nanoparticles is almost identical to that of the microparticles.

7 pages, 8 figures, 2 tables

References in corpus (5)

• Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging
• Dynamical singlets and correlation-assisted Peierls transition in VO2
• Orbital-assisted metal-insulator transition in VO${}_2$
• Electrodynamics of the vanadium oxides VO2 and V2O3
• Evidence of a pressure-induced metallization process in monoclinic VO${}_2$

Cited by in corpus (1)

• Computation of the correlated metal-insulator transition in vanadium dioxide from first principles