Si doping on MgB2 thin films by pulsed laser deposition

TL;DR

This study explores Si doping in MgB2 thin films via pulsed laser deposition, revealing enhanced critical current density and irreversibility field at certain doping levels without significantly affecting the transition temperature.

Contribution

It demonstrates a method for Si doping in MgB2 films and shows improved superconducting properties at specific doping concentrations.

Findings

Critical current density increased by 50% at 5K with 3.5wt% Si doping.

Irreversibility field (Hirr) is higher in Si-doped films at low temperatures.

Transition temperature (Tc) remains largely unchanged up to 11wt% Si doping.

Abstract

A series of MgB2 thin films were fabricated by pulsed laser deposition (PLD), doped with various amounts of Si up to a level of 18wt%. Si was introduced into the PLD MgB2 films by sequential ablation of a stoichiometric MgB2 target and a Si target. The doped films were deposited at 250 C and annealed in situ at 685 C for 1min. Up to a Si doping level of ~11wt%, the superconducting transition temperature (Tc) of the film does not change significantly, as compared to the control, undoped film. The magnetic critical current density (Jc) of the film at 5K was increased by 50% for a Si doping level of ~3.5wt%, as compared to the control film. Also, the irreversibility field of Si-doped MgB2 films (Hirr) at low temperature is higher than for the undoped film.