Superconductivity of FeSe_0.5Te_0.5Thin Films Grown by Pulsed Laser Deposition

Abstract

FeSe0.5Te0.5 thin films with a PbO-type structure are successfully grown on MgO(100) and LaSrAlO4(001) substrates from FeSe0.5Te0.5 or FeSe0.5Te0.75 polycrystalline targets by pulsed laser deposition. The film deposited on the MgO substrate (film thickness: ∼55 nm) shows superconductivity at 10.6 K (onset) and 9.2 K (zero resistivity). On the other hand, the film deposited on the LaSrAlO4 substrate (film thickness: ∼250 nm) exhibits superconductivity at 5.4 K (onset) and 2.7 K (zero resistivity). This suggests the strong effect of substrate materials and/or the c-axis length on the superconducting properties of FeSe0.5Te0.5 thin films.

Tunable critical temperature for superconductivity in FeSe thin films by pulsed laser deposition

“…Therefore, the c -axis lattice constant is more closely related to the superconductivity of FeSe thin films. Comparably, the superconductivity of the multi-layered FeSe-based superconductors, i.e., (Li 1- x Fe x )OHFeSe 34 and Fe(Se 0.5 Te 0.5 ) 35 , shows a similar c -axis constant dependence behavior, which reinforces our understanding on the profile of lattice parameters to the superconductivity. The c -axis lattice parameter depends on the anion height from the Fe layer 4,36,37 (or the bond angle of Se-Fe-Se 4,38 ) and the distance between two adjacent Fe 2 Se 2 layer 39 , which will influence the magnetism and interlayer coupling respectively.…”

Superconducting fluctuations in FeSe0.5Te0.5 thin films probed via microwave spectroscopy

“…FeSe 0.5 Te 0.5 epitaxial films were grown on CaF 2 by a pulsed laser deposition method using a KrF laser [20,21]. FeSe 0.5 Te 0.5 polycrystalline pellets were used as targets.…”

Investigation of Transport Properties for FeSe1−xTex Thin Films under Magnetic Fields

“…FeSe 1Àx Te x polycrystalline pellets (x ¼ 0{0: 8) were used as targets. 11,12) The substrate temperature, laser repetition rate, and base pressure were 280°C, 20 Hz, and 10 À7 Torr, respectively. Commercially available CaF 2 (100) substrates, which are one of the most suitable materials for the thin-film growth of FeSe 1Àx Te x , [12][13][14] were used for the present experiments.…”