Pressure-Induced Metallic Conductivity in the Single-Component Molecular Crystal [Ni(dmit)2]



Given that a molecular system has a soft lattice, high-pressure applications are effective ways to discover new single-component molecular metals and superconductors. In this study, we measured the high-pressure electrical resistivity of a single-component molecule crystal of [Ni(dmit)2] (dmit = 1,3-dithiole-2-thione-4,5-dithiolate) up to 25.5 GPa by using a newly developed diamond anvil cell technique that generates high-quality hydrostatic pressures. We successfully observed the metallic state over a wide temperature range above 15.9 GPa. Two different band calculation methods, tight-binding calculations coupled with the interatomic repulsion model and ab initio DFT calculations, indicated that 2D and 3D Fermi surfaces appear under high pressures.