Exploring Structural Features and Growth Mechanisms in GdBa₂Cu₃O_7- /LaFeO₃ Bilayers on SrTiO₃ Substrates

Area of Science:

• Materials Science
• Condensed Matter Physics
• Superconductivity

Background:

• Superconducting thin films require buffer layers for enhanced performance.
• Rare-earth orthoferrite (REFO) materials have potential as buffer layers.
• Gadolinium barium copper oxide (GdBCO) is a high-performance superconductor.

Purpose of the Study:

• To investigate the effect of lanthanum iron oxide (LFO) buffer layer thickness on GdBCO superconducting thin films.
• To explore the structural and superconducting properties of GdBCO/LFO bilayers.
• To assess the potential of REFO materials as buffer layers in superconductor applications.

Main Methods:

• Fabrication of LFO buffer layers with varying thicknesses (50, 100, 150, 200 nm).
• Deposition of a 200 nm GdBCO layer on LFO to create bilayer structures.
• Characterization of LFO and GdBCO/LFO bilayers, including structural, surface, and strain analysis.

Main Results:

• LFO buffer layers exhibited pseudocubic growth compatible with GdBCO.
• Varying LFO thickness influenced the structural, surface, and strain states of the bilayers.
• Superconducting transition temperature (Tc-onset) of GdBCO consistently improved with LFO buffer layers, reaching up to 92.4 K at 150 nm LFO thickness.

Conclusions:

• Lanthanum iron oxide (LFO) is a viable REFO material for use as a buffer layer in superconductor technology.
• Optimized LFO buffer layer thickness enhances the superconducting properties of GdBCO films.
• REFO materials offer significant potential for improving superconductor performance.