WEB Advances on high-throughput superconductivity researchThursday (24.09.2020) 10:10 - 10:40 M: Modelling and Simulation 2 Part of:
In this talk, I will brieﬂy review the history of high-throughput research and then focus on some recent applications in superconductivity research.
I will first show a high-throughput process from sample preparation to data library on La2-xCexCuO4 (LCCO) superconductor, demonstrating the concept of experimental data matching over multiscale space. We succeeded in growing epitaxial LCCO film on 1 cm (00l)-SrTiO3 substrate by the combinatorial laser MBE technique, spreading from x = 0.10 to 0.19. Such combinatorial films are suitable for multiscale fast screening, and help us to obtain i) a lattice-doping library by high-throughput in-lab XRD and synchrotron XRD facilities, with the space resolution reduced from millimeter down to micrometer; ii) quantitative Tc(x) relation based on the electrical transport database on a single chip that contains hundreds of resistivity data sets; iii) a textbook behavior of penetration depth by two-coil mutual inductance and scanning SQUID techniques. These combinatorial films are being used for pump-probe, XAS, RIXS measurements, to explore the systematical behavior without missing subtle feature..
In the second part, I will introduce a new fabrication method based on lattice structure modulation. The core idea is the construction of a dual-beam pulsed laser deposition (PLD) technique, successfully applied on FeSe and BaTiO3 systems. After 10 years of intensive research, the Tc-lattice relation of FeSe superconductor remains elusive. It is encouraging that the new method can assist in growing FeSe film with gradient Tc (e.g. from 0 to 12 K). Consequently, we built the Tc-lattice library on single FeSe chip within several weeks and obtained an unambiguous relation. This is in sharp contrast to the scatter Tc-lattice plot from over 1000 uniform films in 3 years by traditional PLD. Owing to the reference library, we can choose the right uniform samples for a comprehensive study, and link the Tc evolution and enhancement to local lattice distortions, rather than off-stoichiometric defects or doping effect. This is a key in understanding the nature of FeSe superconductor.
Finally, I will exhibit our homemade combi laser MBE integrated with an in-situ low temperature STM system, a gem of 4-year effort, and introduce the design principles of Beijing Materials Genome Initiative Center.