Superconductivity in Ti-doped Iron-Arsenide Compound Sr4Cr0.8Ti1.2O6Fe2As2

TL;DR

This paper reports the discovery of superconductivity in Ti-doped Sr4Cr0.8Ti1.2O6Fe2As2, with bulk superconductivity confirmed at 6 K and an onset transition at 29.2 K, highlighting the effects of doping and phase composition.

Contribution

It presents the synthesis and characterization of a new Ti-doped iron-arsenide superconductor with detailed structural and superconducting property analysis.

Findings

Bulk superconductivity confirmed at 6 K

Onset transition temperature at 29.2 K

Layered structure with P4/nmm space group

Abstract

Superconductivity was achieved in Ti-doped iron-arsenide compound Sr4Cr0.8Ti1.2O6Fe2As2 (abbreviated as Cr-FeAs-42622). The x-ray diffraction measurement shows that this material has a layered structure with the space group of \emph{P4/nmm}, and with the lattice constants a = b = 3.9003 A and c = 15.8376 A. Clear diamagnetic signals in ac susceptibility data and zero-resistance in resistivity data were detected at about 6 K, confirming the occurrence of bulk superconductivity. Meanwhile we observed a superconducting transition in the resistive data with the onset transition temperature at 29.2 K, which may be induced by the nonuniform distribution of the Cr/Ti content in the FeAs-42622 phase, or due to some other minority phase.