Temperature-concentration phase diagram of (Ca1-xLax)10(Pt3As8)(Fe2As2)5 superconductors

TL;DR

This study investigates the phase diagram of (Ca1-xLax)10(Pt3As8)(Fe2As2)5 superconductors, revealing how La doping suppresses structural and magnetic transitions and induces a superconducting dome with a maximum Tc of 26 K.

Contribution

It provides the first detailed temperature-concentration phase diagram for this superconductor family, highlighting the effects of La doping on phase transitions and superconductivity.

Findings

Superconductivity appears with La doping, peaking at 26 K.

Structural and magnetic transitions are suppressed by La doping.

A superconducting dome is mapped out in the phase diagram.

Abstract

Single crystals of (Ca1-xLax)10(Pt3As8)(Fe2As2)5 (x = 0 to 0.182) superconductors have been grown and characterized by X-ray, microprobe, transport and thermodynamic measurements. Features in the magnetic susceptibility, specific heat and two kinks in the derivative of the electrical resistivity around 100 K in the x = 0 compound support the existence of decoupled structural and magnetic phase transitions. With La doping, the structural/magnetic phase transitions are suppressed and a half-dome of superconductivity with a maximal Tc around 26 K is observed in the temperature-concentration phase diagram.