Effect of thickness on the superconducting properties of the thin films of FeTe_0.55Se_0.45 deposited on YSZ substrates using Pulsed laser deposition (PLD) technique

Abstract

We report the successful fabrication of thin films of thickness ~26 nm, 59 nm, 76 nm, and 158 nm of the composition FeTe0.55Se0.45 on the (100)-oriented Yttria-stabilized zirconia (YSZ) substrate using the pulsed laser deposition (PLD) technique. The effect of thickness on the structure and superconducting properties of the thin films has been investigated. X-ray diffraction study reveals the growth of thin films along the c-axis. The temperature-dependent resistivity measurements confirm superconductivity in all the fabricated thin films, and the highest Tconset ~16.2 K has been observed for the thin film of thickness ~59 nm, which is higher than the corresponding value of the polycrystalline target sample. The superconducting parameters such as upper critical magnetic field Hc20, coherence length ξ0, thermally activated energy (TAE) U0, and vortex phase state have been measured by magnetotransport measurements near Tc in the different applied magnetic fields up to 12 T. The TAE values determined from the conventional and modified thermally activated flux flow (TAFF) models are discussed and compared. A crossover from 2-dimensional (2D) vortex to 3-dimensional (3D) vortex behaviour has been observed. The vortex phase diagrams are used to observe the transition from the vortex liquid to the vortex glass state in the grown thin films. Moreover, magnetoresistance (MR) measurements show non-saturating linear magnetoresistance (LMR) in the high field region, indicating the presence of the possible topological state in the grown thin films. The values of magnetic field dependent transport critical current density, JcH have been evaluated from the current-voltage (I-V) curves. Furthermore, the normalised pinning force density has been used to characterize the pinning processes using the Dew Hughes’ scaling rule which reveals that the grown thin films contain δl-surfacepinning centers.

Investigation on Magnetotransport Properties and Specific Heat Capacity of FeTe0.58Se0.42 Single Crystals Grown by Self‐Flux Method

“…[10][11][12] Also, these FCSs are important for practical applications due to their high H C2 and J C . [13][14][15] The Fe(Te,Se) single crystals exhibit anisotropy in field-dependent transport and magnetic measurements [11,16,17] and the mixed state phenomena for different compositions. [10,[18][19][20] The thermally activated flux flow (TAFF) model has been utilized to study the vortex phase diagram of FBSCs.…”

“…[ 10–12 ] Also, these FCSs are important for practical applications due to their high H C2 and J C . [ 13–15 ]…”