Work

Enhancement of the Superconducting Transition Temperature in Mn-doped CaKFe4As4 Processed by the High gas-pressure and High-temperature Synthesis Method

Year: 2025

Type: article

Abstract: A series of Mn-doped CaKFe 4 As 4 samples, CaK(Fe 1 − x Mn x ) 4 As 4 with x values of 0, 0.005, 0.01, 0.02, 0.03, 0.04, and 0.05, are synthesized using two distinct routes: conventional synthesis process at ambient pressure (CSP), and high gas-pressure and high-temperature synthesis (HP-HTS) method. Comprehensive characterizations are performed on these samples to investigate their superconducting properties. This study examines the effects of Mn substitution at Fe sites in the FeAs layer on the superconducting properties of the CaKFe 4 As 4 (1144) material. The HP-HTS process improves the microstructure and phase purity of the parent sample ( x = 0), resulting in an enhanced superconducting transition temperature ( T c ). In contrast, Mn doping via the CSP method in CaKFe 4 As 4 reduces the sample quality and superconducting performance. Notably, the high-pressure synthesis method leads to an increase in the T c by 3 to 7 K, particularly at low Mn concentrations. While the critical current density ( J c ) of the parent sample ( x = 0) shows a significant enhancement under the applied magnetic fields, J c decreases for Mn-doped CaKFe 4 As 4 bulks. These results demonstrate that high-pressure synthesis is an effective approach to improve the superconducting properties of Mn-doped 1144 compounds.

Source: Journal of Superconductivity and Novel Magnetism

DOI: 10.1007/s10948-025-07115-2