Suppression of electronic susceptibility in metal-Mott insulator alternating material, (Me-3,5-DIP)[Ni(dmit)2]2

TL;DR

This study investigates the magnetic and electronic properties of a layered metal-Mott insulator compound using 13C NMR, revealing antiferromagnetic order in the insulator and suppression of electronic susceptibility in the metal due to interlayer coupling.

Contribution

It provides new insights into the coexistence of metallic and insulating layers and the suppression of susceptibility caused by interlayer interactions in this material.

Findings

Insulating layer undergoes antiferromagnetic order at 2.5 K.

Significant suppression of conduction electron susceptibility below 35 K.

Evidence of strong c-c_loc coupling affecting electronic states.

Abstract

Frequency shifts and nuclear relaxations of 13C NMR of the metal-insulator alternating material, (Me-3,5-DIP)[Ni(dmit)2]2, are presented. The NMR absorption lines originating from metallic and insulating layers are well resolved, which evidences the coexistence of localized spins (\pi_loc) and conduction \pi-electrons. The insulating layer is newly found to undergo antiferromagnetic long range order at about 2.5 K, suggesting emergence of S=1/2 Mott insulator. In the metallic layer, we found significant suppressions of static and dynamical susceptibilities of conduction electrons below 35 K, where antiferromagnetic correlation in the insulating layer evolves. We propose a dynamical effect through strong \pi-\pi_loc coupling between the metallic and insulating layers as an origin of the reduction of the density of states.