YBaCuO deposition by MOCVD on metallic substrates: a comparative study on buffer layers

Abstract

YBaCuO films of about 1 pm thickness have been deposited by Metal organic chemical vapor deposition (MOCVD) on biaxially textured Ni-based substrates. Different buffer layers (MgO, YSZ, CeOz), and also NiO epitaxially grown on Ni, have been tested with subsequent YBCO deposition in the same reactor. When using NiO as first buffer layer, Ni-based substrates were oxidized in a Rapid thermal processing system or in a conventional furnace previous to deposition of the second buffer layer. In the present work, we study different conductor architectures from the point of view of Tc, Jc(77K), epitaxial growth, and chemical stability of the structure.

Synthesis and Characterization of Volatile, Fluorine-Free β-Ketoiminate Lanthanide MOCVD Precursors and Their Implementation in Low-Temperature Growth of Epitaxial CeO2 Buffer Layers for Superconducting Electronics

“…1 H NMR (400 MHz, C 6 D 6 , δ): -8.0, -5. 5 Single-Crystal X-ray Diffraction Studies. X-ray data for single crystals of lanthanide complexes 4-7, 9, 10, and 12 [grown from pentane solution and mounted on a glass fiber with Paratone-N (Exxon)] were collected on a CCD area detector with graphitemonochromated Mo KR radiation.…”

“…The growth and properties of lanthanide-containing oxide films is of great current interest to the chemistry, materials science, and electronics communities. − Applications include multilayer device buffer layers (e.g., CeO 2 ), − high dielectric constant (high- k ) materials (e.g., Gd 2 O 3 ), , high- temperature superconductors (e.g., LnBa 2 Cu 3 O 7 - δ ), − phosphor dopants, − solid-state oxide fuel cells, and magnetic materials …”

“…The growth and properties of lanthanide-containing oxide films is of great current interest to the chemistry, materials science, and electronics communities. [1][2][3][4] Applications include multilayer device buffer layers (e.g., CeO 2 ), [5][6][7][8][9][10][11][12] high dielectric constant (high-k) materials (e.g., Gd 2 O 3 ), 13,14 temperature superconductors (e.g., LnBa 2 Cu 3 O 7-δ ), [15][16][17] phosphor dopants, 18-21 solid-state oxide fuel cells, 22 and magnetic materials. 23 MOCVD (metal-organic chemical vapor deposition) offers many attractions for oxide film growth, including low equipment costs, straightforward scale-up, conformal deposition on a variety of complex substrates, low growth temperatures, and rapid growth rates.…”

“…In this contribution, lanthanide β-ketoiminate complexes of type VIII are named according to the substitution at the R 1 , R 2 , and R 3 sites, "Ln(R 1 R 2 R 3 ) 3 ," and the noncoordinated protonated ligands are simply "H(R 1 R 2 R 3 )." CeO 2 , with a cubic fluorite crystal structure (a ) 5.411 Å), 83 has been widely investigated as a protective buffer layer for high-temperature superconductor (HTS) films in currentcarrying applications [5][6][7][8][9] and as an insulating layer in multilayer electronic devices. [10][11][12] Compared to YSZ, CeO 2 is a more attractive buffer layer for superconducting YBa 2 Cu 3 O 7-δ (YBCO) because of the smaller lattice mismatch and similar thermal expansion coefficient.…”