Electronic and Magnetic Properties of π–dInteraction System (EDTDM)2FeBr4

Abstract

The crystal structure and electronic and magnetic properties of magnetic molecular conductor (EDTDM) 2 FeBr 4 are investigated. The material undergoes a SDW transition at T MI ∼11 K and an antiferromagnetic transition of Fe 3+ d -spins at T N =3 K. In addition to the appearance of an anomaly in the resistivity around T N , a large magnetoresistance is observed below T N , which diverges at the critical pressure ( P c ∼9.2 kbar) of the MI transition. The perturbation potential from the antiferromagnetic Fe 3+ spin arrangement stabilizes the SDW state, leading to the anomaly in the resistivity. The application of magnetic field reduces the potential of the Fe 3+ spins, which leads to the large negative magnetoresistance. This indicates that the π– d interaction plays an important role in the interplay between the magnetism and the electron transport.