Nanodiamond Influence on the Nucleation and Growth of YBCO Superconducting Film Deposited by Metal–Organic Decomposition

Abstract

It was recently shown that the introduction of nanodiamond (ND) into a superconducting metal–organic deposited YBa2Cu3O7−δ (YBCO) film produces an increase in critical current density in self-field conditions (B = 0 T). Such improvement appears to be due to the formation of denser and smoother films than the samples deposited without ND. This paper presents the work done to understand the role of ND during YBCO nucleation and growth. A detailed study on YBCO+ND films quenched at different temperatures of the crystallization process was carried out. Results showed that the reaction responsible for YBCO production appeared effectively affected by ND. In particular, ND stabilizes one of the YBCO precursors, BaF2(1–x)O x , whose conversion into YBCO requires a prolonged time. Therefore, the YBCO nucleation is slowed down by ND and begins when the experimental conditions favor both thermodynamically and kinetically the formation of YBCO along the c-axis. This effect has important implications because the growth of a highly epitaxial c-axis YBCO film enables excellent superconducting performance.

Preparation of MgO Self-Epitaxial Films for YBCO High-Temperature Coated Conductors

“…REBa 2 Cu 3 O 7− x (REBCO) superconducting conductors exhibit excellent electrical properties and broad application prospects in the fields of transmission cables, strong magnets, motors, and current limiters [1][2][3][4][5][6]. In order to realize the application of high-temperature superconducting materials in the field of transmission cables, the critical current (Ic) must be as high as 200 A/cm at 77 K self-field [7]; therefore, the REBCO conductors must be epitaxially grown on the metal substrates with biaxial texture by the thin film deposition method to avoid grain boundary misalignment [8].…”