Emergent superconductivity in an iron-based honeycomb lattice initiated by pressure-driven spin-crossover

• Published in: Nature communications Vol. 9; no. 1; pp. 1914 - 7
• Main Authors: Wang, Yonggang, Ying, Jianjun, Zhou, Zhengyang, Sun, Junliang, Wen, Ting, Zhou, Yannan, Li, Nana, Zhang, Qian, Han, Fei, Xiao, Yuming, Chow, Paul, Yang, Wenge, Struzhkin, Viktor V., Zhao, Yusheng, Mao, Ho-kwang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15-05-2018; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/1003; 639/638/298/924; Compression; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Crossovers; Crystal structure; External pressure; Honeycomb construction; Humanities and Social Sciences; Iron; Laboratories; Magnetic moments; Metals; multidisciplinary; Organic chemistry; Phase transitions; Pressure; Science; Science (multidisciplinary); Superconductivity; Symmetry; Transition temperature; Transition temperatures
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04326-1

The discovery of iron-based superconductors (FeSCs), with the highest transition temperature (
T
c
) up to 55 K, has attracted worldwide research efforts over the past ten years. So far, all these FeSCs structurally adopt FeSe-type layers with a square iron lattice and superconductivity can be generated by either chemical doping or external pressure. Herein, we report the observation of superconductivity in an iron-based honeycomb lattice via pressure-driven spin-crossover. Under compression, the layered FeP
X
3
(
X
 = S, Se) simultaneously undergo large in-plane lattice collapses, abrupt spin-crossovers, and insulator-metal transitions. Superconductivity emerges in FePSe
3
along with the structural transition and vanishing of magnetic moment with a starting
T
c
 ~ 2.5 K at 9.0 GPa and the maximum
T
c
 ~ 5.5 K around 30 GPa. The discovery of superconductivity in iron-based honeycomb lattice provides a demonstration for the pursuit of transition-metal-based superconductors via pressure-driven spin-crossover.
Up to now, all iron-based high-
T
c
superconductors contain a square iron lattice. Here, Wang et al. report the observation of superconductivity in an iron honeycomb lattice accompanied with pressure-driven spin-crossover, in-plane lattice collapse and insulator-metal transition.