Staggered Spin Order of Localized pi-electrons in the Insulating State of the Organic Conductor kappa-BETS)2Mn[N(CN)2]3

TL;DR

This study reveals that in the organic conductor kappa-BETS)2Mn[N(CN)2]3, pi-electron spins order in a staggered pattern during the insulating transition, which can be suppressed by pressure, maintaining metallicity.

Contribution

The paper demonstrates the magnetic ordering of pi-electrons in an organic conductor and how pressure influences the metal-insulator transition and spin order.

Findings

Pi-spin ordering occurs at the metal-insulator transition.

Applying pressure suppresses the transition, preserving metallic behavior.

Long-range staggered spin structure is observed in the insulating state.

Abstract

Magnetic properties of the conduction pi-electron system of kappa-BETS)2Mn[N(CN)2]3 have been probed using 13C NMR. At ambient pressure, the metal-insulator transition observed in the resistivity measurements below T~23K is shown to be accompanied by ordering of the pi-spins in a long-range staggered structure. As the metal-insulator transition is suppressed by applying a small pressure of ~0.5 kbar, the pi-spin system maintains the properties of the metallic state down to 5K.