Preparation and optimization of high-temperature superconducting Ruddlesden-Popper nickelate thin films

Abstract

The discovery of ambient-pressure nickelate high-temperature superconductivity provides a new platform for probing the underlying superconducting mechanisms. However, the thermodynamic metastability of Ruddlesden-Popper nickelates Lnn+1NinO3n+1 (Ln = lanthanide) presents significant challenges in achieving precise control over their structure and oxygen stoichiometry. This study establishes a systematic approach for growing phase-pure, high-quality Ln3Ni2O7 thin films on LaAlO3 and SrLaAlO4 substrates using gigantic-oxidative atomic-layer-by-layer epitaxy. The films grown under an ultrastrong oxidizing ozone atmosphere are superconducting without further post annealing. Specifically, the optimal Ln3Ni2O7/SrLaAlO4 superconducting film exhibits an onset transition temperature (Tc,onset) of 50 K. Four critical factors governing the crystalline quality and superconducting properties of Ln3Ni2O7 films are identified: 1) precise cation stoichiometric control suppresses secondary phase formation; 2) complete atomic layer-by-layer coverage coupled with 3) optimized interface reconstruction minimizes stacking faults; 4) accurate oxygen content regulation is essential for achieving a single superconducting transition and high Tc,onset. These findings provide valuable insights for the layer-by-layer epitaxy growth of diverse oxide high-temperature superconducting films.

References in corpus (14)

• Superconductivity near 80 Kelvin in single crystals of La3Ni2O7 under pressure
• Superconducting Dome in Nd${}_{1-x}$Sr${}_x$NiO${}_2$ Infinite Layer Films
• Electronic structure of the parent compound of superconducting infinite-layer nickelates
• Phase diagram and superconducting dome of infinite-layer $\mathrm{N}{\mathrm{d}}_{1-\mathrm{x}}\mathrm{S}{\mathrm{r}}_{\mathrm{x}}\mathrm{Ni}{\mathrm{O}}_2$ thin films
• Superconductivity in pressurized trilayer La${}_4$Ni${}_3$O${}_{10-\delta }$ single crystals
• Effective bi-layer model Hamiltonian and density-matrix renormalization group study for the high-Tc superconductivity in La${}_3$Ni${}_2$O${}_7$ under high pressure
• Signature of superconductivity in pressurized La${}_4$Ni${}_3$O${}_{10}$
• Character of the "normal state" of the nickelate superconductors
• Structural transition, electric transport, and electronic structures in the compressed trilayer nickelate La4Ni3O10
• Electronic Origin of High-Tc Maximization and Persistence in Trilayer Cuprate Superconductors
• Strain-tuning for superconductivity in La${}_3$Ni${}_2$O${}_7$ thin films
• Inequalities for low-energy symmetric nuclear matter
• Gigantic-oxidative atomic-layer-by-layer epitaxy for artificially designed complex oxides
• Perspective: imaging atomic step geometry to determine surface terminations of kagome materials and beyond

Cited by in corpus (2)

• Superconductivity and Electronic Structures of Nickelate Thin Film Superstructures
• Compressive Strain Turns $s^{\pm }$ into $d$-Wave Pairing in One-unit-cell La${}_3$Ni${}_2$O${}_7$ Thin Film Via Substrate-Induced Hole Doping