Strategies for Iron Based Coated Conductors: learning from HTS

HIBiSCUS

 

Duration: 36 months

Start date: August 19°, 2019

Projet Coordinator: Marina Putti

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Funding agency: Ministero dell’Istruzione, dell’Università e della Ricerca, MIUR

PRIN: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE – Bando 2017

Prot. 201785K

 

 

Background

The discovery of a new superconductor is always welcomed by enormous excitement in the scientific world, not only to the charm of this property, but also to the hope for a practical use as conductors for carrying current and producing high magnetic fields. This was exactly the vision descripted by Kamerlingh Onnes in 1913 [i], two years after his discovery of superconductivity in Hg. Noticeably, the first superconducting wires based on Nb alloys optimized to carry high current appeared only in the 1960s. Another striking example was the discovery of the high-temperature superconductors (HTS) by Bednorz and Müller in 1986 [ii]. The two distinguished scientists were awarded the Nobel Prize less than a year after their discovery, demonstrating that the hopes for the potential of the new superconductors were enormous. Unfortunately, the expectations for easy use of HTS conductors cooled in liquid nitrogen have been infringed by the many complexities associated with their structure (strongly anisotropic) and by the unconventional nature of the pairing mechanisms, until then not yet explored. More than 30 years since the HTS discovery most of these issues have been solved, but the fabrication of HTS superconducting wires/tapes is extremely expensive because of the complicated fabrication processes. In 2008 we celebrated the discovery of Fe-based superconductors (IBS) by the Hosono group [iii]. The properties of these materials are extremely interesting from an applicative point of view, in particular for the generation of high magnetic fields.

  1. K. Onnes, Commun.Physical Lab. 133 (1913) 37.
  2. J. G. Bednorz, K.A. Müller, Z. Phys. B 64 (2) (1986) 189.
  3. Y. Kamihara et al., J. Am. Chem. Soc. 130 (11) (2008) 3 296.

 

Objectives

The aim of the project is to develop the methodology for realizing IBS conductors for high field application. We will follow the road opened by HTS with the belief that IBSs have many advantages in terms of complexity and costs abatement that can make this technology promising to replace the use of Nb3Sn in the implementation of future accelerators and nuclear fusion plants.

HIBiSCUS aims at developing an exploitable method for the fabrication of a coated conductor (CC) prototype of the 11 phase with optimized pinning properties, so as to meet the requirements for the target for industrial applications (Jc = 0.1 MA/cm2 @ 4.2 K and 10 T, and production cost significantly reduced with respect to the present HTS technology. The 11 phase among IBS families is chosen because 11-CC present the most outstanding superconducting properties, do not contain toxic elements and can be easily prepared following fabrication route matching the scalability required by applications.