Temperature-pressure phase diagram and electronic properties of the organic metalκ−(BETS)2Mn[N(CN)2]3

Abstract

The crystal and electronic band structures as well as the transport properties of the recently synthesized layered radical cation salt -BETS2MnNCN23 are investigated. It is shown that this salt is more anisotropic in the plane of conducting layers than other phases, a feature which noticeably influences its physical behavior. A phase transition resulting in the formation of an incommensurate superstructure below 102 K has been found. At temperature below 3 0Kam etal-insulator transition is observed. We argue that the transition is associated with electronic interactions rather than with structural changes. The T-P phase diagram has been studied under 4 He gas pressure up to 2.5 kbar. At moderately high pressure P0.5 kbar the metal-insulating transition is suppressed and the crystal becomes superconducting with Tc5.7 K. In the pressurized metallic state, Shubnikov-de Haas oscillations have been found, revealing a very small closed Fermi surface with a high-effective cyclotron mass influenced by many-body interactions.