Magnetic-field-induced transition in BaVS3

TL;DR

This study investigates how magnetic fields influence the metal-insulator transition in BaVS3 near critical pressure, revealing that magnetic fields broaden the transition and can induce metallicity when the transition temperature is sufficiently low.

Contribution

It provides detailed magnetoresistivity measurements near the critical pressure, showing the magnetic field's role in broadening the transition and inducing metallic behavior in BaVS3.

Findings

Magnetic fields broaden the MIT in BaVS3.

Transition can be driven to metallic state by magnetic field at low T_MI.

Magnetic correlations are linked to structural tetramerization.

Abstract

The metal-insulator transition (MIT) of BaVS3 is suppressed under pressure and above the critical pressure of p~2GPa the metallic phase is stabilized. We present the results of detailed magnetoresistivity measurements carried out at pressures near the critical value, in magnetic fields up to B=12T. We found that slightly below the critical pressure the structural tetramerization -- which drives the MIT -- is combined with the onset of magnetic correlations. If the zero-field transition temperature is suppressed to a sufficiently low value (T_MI<15K), the system can be driven into the metallic state by application of magnetic field. The main effect is not the reduction of T_MI with increasing B, but rather the broadening of the transition due to the applied magnetic field. We tentatively ascribe this phenomenon to the influence on the magnetic structure coupled to the bond-order of the tetramers.