Pinto Valentina, Vannozzi Angelo, Celentano Giuseppe, Tomellini Massimo, Meledin Alexander, Orlanducci Silvia
Superconductivity Laboratory, FSN-COND, ENEA, Via E. Fermi 45, 00044 Frascati (Rome), Italy.
Department of Chemical Sciences and Technologies, Via della Ricerca Scientifica, Tor Vergata University, Rome 000173, Italy.
Cryst Growth Des. 2023 Jul 15;23(8):6086-6099. doi: 10.1021/acs.cgd.3c00607. eCollection 2023 Aug 2.
It was recently shown that the introduction of nanodiamond (ND) into a superconducting metal-organic deposited YBaCuO (YBCO) film produces an increase in critical current density in self-field conditions ( = 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, BaFO, 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 -axis. This effect has important implications because the growth of a highly epitaxial -axis YBCO film enables excellent superconducting performance.
最近的研究表明，将纳米金刚石（ND）引入超导金属有机沉积的YBaCuO（YBCO）薄膜中，会使自场条件下（ = 0 T）的临界电流密度增加。这种改善似乎是由于与未添加ND的样品相比，形成了更致密、更光滑的薄膜。本文介绍了为了解ND在YBCO成核和生长过程中的作用所做的工作。对在结晶过程的不同温度下淬火的YBCO+ND薄膜进行了详细研究。结果表明，负责YBCO生成的反应似乎受到ND的有效影响。特别是，ND使YBCO前体之一BaFO稳定，其转化为YBCO需要较长时间。因此，ND减缓了YBCO的成核，并且在实验条件在热力学和动力学上都有利于沿轴形成YBCO时才开始。这种效应具有重要意义，因为高度外延的轴YBCO薄膜的生长能够实现优异的超导性能。
