Local spin and charge properties of beta-Ag0.33V2O5 studied by 51V NMR

TL;DR

This study used 51V-NMR and ZFR techniques to analyze local spin and charge properties of beta-Ag0.33V2O5, revealing charge-sharing among vanadium sites and their local environments in different phases.

Contribution

It provides detailed NMR characterization of inequivalent vanadium sites and their charge-sharing behavior in beta-Ag0.33V2O5, a pressure-induced superconductor.

Findings

Identified three inequivalent V sites via NMR spectra.

Determined electric-field-gradient tensor axes in different phases.

Supported a charge-sharing model with 3d1 electrons within ladders.

Abstract

Local spin and charge properties were studied on beta-Ag0.33V2O5, a pressure-induced superconductor, at ambient pressure using 51V-NMR and zero-field-resonance (ZFR) techniques. Three inequivalent Vi sites (i=1, 2, and 3) were identified from 51V-NMR spectra and the principal axes of the electric-field-gradient (EFG) tensor were determined in a metallic phase and the following charge-ordering phase. We found from the EFG analysis that the V1 sites are in a similar local environment to the V3 sites. This was also observed in ZFR spectra as pairs of signals closely located with each other. These results are well explained by a charge-sharing model where a 3d1 electron is shared within a rung in both V1-V3 and V2-V2 two-leg ladders.