A Heterolayered Fe-based Silicide Superconductor

Superconductivity is among the most intensively sought states of matter. However, the discovery of new superconductors often occurs by chance from a wide range of materials largely due to the lack of understanding of the true nature of superconductivity. Significantly, the discovery of cuprate and Fe-based superconductors, many of which contain heterolayered building blocks of [CuO₂]^2- and [FeAs]^- layers respectively, suggests a rational design approach for unconventional superconductors by combining functional layers with non-magnetic spacer layers, indicating the potential for a systematic approach to discovering new superconductors

Here we demonstrate an encouraging example of this strategy with a newly synthesized Fe-based Heterolayered Silicide, Y₄FeSi₈, in single-crystal form. The crystal structure of Y₄FeSi₈ consists of two distinct functional layers (of edge-sharing Fe-Si square pyramidal) separated by non-magnetic spacer layers ( of double vertical honeycomb Y-Si layers). The synthesis method of this new heterolayered Fe-based silicide will be discussed along with physical properties confirming the superconductivity transition.