FeSe(en)0.3 - Separated FeSe layers with stripe-type crystal structure by intercalation of neutral spacer molecules

TL;DR

This study explores the intercalation of ethylenediamine molecules into FeSe, creating a layered structure with a stripe-type crystal arrangement, but without superconductivity unless electron-doped, highlighting structural effects on superconductivity.

Contribution

It introduces a new intercalated FeSe compound with separated layers and analyzes its structural and electronic properties compared to superconducting FeSe.

Findings

Intercalation separates FeSe layers by 1078 pm.

FeSe(en)0.3 is not superconducting without doping.

Electron doping is necessary for high Tc in this structure.

Abstract

Solvothermal intercalation of ethylenediamine molecules into FeSe separates the layers by 1078 pm and creates a different stacking. FeSe(en)0.3 is not superconducting although each layer exhibits the stripe-type crystal structure and the Fermi surface topology of superconducting FeSe. FeSe(en)0.3 requires electron-doping for high-Tc similar to monolayers of FeSe@SrTiO3, whose much higher Tc may arise from the proximity of the oxide surface.