Lavinia Saltarelli will defend her PhD thesis on Fri, 14 June 2024 at ICMAB
The PhD candidate Lavinia Saltarelli from the SUMANgroup at ICMAB-CSIC, will defend her PhD thesis on Fri, 14 June 2024 2024 at ICMAB.
TLAG of solution-derived REBCO superconducting films: ultrafast growth mechanism and influence of transient liquid composition
Date: Friday, 14 June 2024
Time: 11AM
Venue: Institut de Ciència de Materials de Barcelona (ICMAB, CSIC) – Sala d’Actes Carles Miravitlles
Abstract
The unparalleled feature of High Temperature Superconducting (HTS) materials of lossless electrical current conduction up to liquid nitrogen temperature and at high magnetic fields has encouraged research on REBa2Cu3O7-δ (REBCO, RE= rare earth elements) systems to unravel the opportunities towards a plethora of different applications. Nonetheless, the excessive production costs of the commercialized HTS Coated Conductors (CCs) are impeding their worldwide spread. The work conducted in this thesis sets as an objective the reduction of the high cost/performance ratio of REBCO superconductors by coupling a cost-effective chemical solution deposition-based (CSD) methodology to the innovative transient liquid assisted growth (TLAG) process. The development of novel, robust chemical solutions led to the attainment
of unprecedented chemical and microstructural homogeneity of films showing thickness of up to 2.7 mm, through implementation of two fundamental innovations. High-purity metal propionate powder precursors have been synthesized through facile and inexpensive one-pot methods. Additionally, the careful selection of an amine additive enhanced the rheological properties of the chemical precursor solution for YBCO and REBCO film fabrication. Variation of the (Ba:Cu) molar ratio of the initial chemical solution resulted in films of different transient liquid composition, enabling the in-depth analysis of the out-of-equilibrium kinetic mechanism of TLAG. Strict control of the processing parameters led to high-performance films exhibiting critical current density values up to 3 MA cm−2 and growth rates beyond 2000 nm·s−1. Advanced characterization techniques, such as in-situ synchrotron X-ray diffraction, shed light on the influence of transient liquid supersaturation, driving force towards YBCO nucleation and its successive epitaxial growth. These analyses have generated new and fundamental insights into the complex kinetic mechanism of TLAG.
Supervisors:
Prof. Teresa Puig
Prof. Xavier Obradors
PhD comitee:
President: Prof. Maarit Karppinen, Aalto University, Finland.
Secretary: Felip Sandiumenge Ortiz, ICMAB-CSIC, Spain.
Vocal: Eduardo Solano Minuesa, ALBA synchroton, Spain.
University: Universitat Autònoma de Barcelona (UAB)
PhD Programme: Material Science
