Shivam Miglani1,Himanshu Chauhan1,Ghanshyam Varma1
Indian Institute of Technology Roorkee1
Shivam Miglani1,Himanshu Chauhan1,Ghanshyam Varma1
Indian Institute of Technology Roorkee1
Since the initial discovery of superconductivity in iron-based superconductors (IBSs), thin films of Fe (Te, Se) superconductors are at the forefront of research in condensed matter physics and materials science. For the development of advanced superconducting devices, it is essential to fabricate the high-quality epitaxial thin films of IBSs. In recent years, several groups have been trying to understand the origin of topological states in thin films, but so far there is not much experimental agreement on these issues, and further studies are needed. In this approach, we have fabricated FeTe<sub>0.55</sub>Se<sub>0.45</sub> thin film of different thicknesses on Yttria-stabilized zirconia (YSZ) single-crystalline substrates using pulsed laser deposition (PLD) technique. The effects of thickness on the structural, superconducting, and topological properties have been systematically investigated. The superconductivity in the grown thin film has been affirmed by the temperature-dependent resistivity measurements. It has been observed that superconducting transition temperature vary with the thickness of the films. Superconducting parameters such as upper critical field H<sub>C2</sub>(0) and corresponding coherence lengths (ξ) and activation energy (U<sub>0</sub>) have been estimated using magnetotransport measurements. In addition, a non-saturating linear magnetoresistance (LMR) is also observed, suggesting the presence of a possible topological superconducting state in the grown thin films. Furthermore, current-voltage (<i>I–V</i>) measurements have been used to calculate transport critical current density, <i>J</i><sub>C</sub> of the grown thin films. In this paper a detail correlation between thickness and observed superconducting properties of the grown thin films will be presented and discussed. The study of the presence of possible topological phase in the grown film is relevant to the current focus of developing quantum devices.