Spontaneous Antiferromagnetic Ordering in a Single Layer of (BETS)2GaCl4 Organic Superconductor

Scanning tunneling microscopy and spectroscopy are presented to study the interplay between superconductivity and magnetism in a single-layer organic d-wave superconductor (BETS)(2)GaCl(4)on Ag(111). Antiferromagnetic molecular chains of GaCl(4)are spontaneously formed within (BETS)(2)GaCl(4)superconducting single layer due to shortages of BETS dimers. Below transition temperature of 7 K, the superconducting order masks the antiferromagnetic order and dominates the electronic properties, showing a ubiquitous gap over the entire island with proximity effect across the island/Ag(111) interface. These features gradually decay with the rise in temperature giving way to a Kondo dip on GaCl(4)chains, with additional inelastic vibronic features on (BETS)(2)GaCl(4)stripes. The concurrent absence of these signals belowT(c)may be related to a renormalization process where both phonon and antiferromagnetic fluctuation exhibit a cooperative existence to mediate superconductivity in such d-wave superconductors.