Development of an MgB2 superconducting wire with introduction of artificial pinning centers

• Grant number: 15/09041-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2015
• Effective date (End): June 30, 2016
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Lucas Barboza Sarno da Silva
• Grantee: Rodrigo Godoy de Souza
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

Among the superconductors that can be used in practical applications, the MgB2 is still considered the high field conductor of the future, due to their exceptionally high values of critical field (~ 40T) and critical temperature (~ 35-40K). Another important property for practical applications is the critical current density. The optimization of the magnetic flux pinning in these conductors is extremely important to increase the critical currents. The introduction of doping and intragranular or intergranular phases in the superconducting matrix can aid the pinning efficiency and grain connectivity, as well as to affect the superconducting phase by changing in the resistivity, upper critical field and critical temperature. In previous studies, structural defects were introduced in the superconducting matrix by compounds with additions of AlB2 crystalline structure type, the same hexagonal C32 structure as MgB2, maintaining the phase structures unchanged (DA SILVA, 2013). Also the simultaneous doping of metal diborides and carbon sources (SiC, carbon nanotubes and graphite) were analyzed. Interesting superconducting and pinning behaviors for practical applications were obtained using compounds with distinct MgB2 electrical and magnetic characteristics.This project suggests the use of optimized results of addition new elements to the MgB2 matrix (DA SILVA, 2013) to define the superconducting powder to be used in the manufacture of an MgB2 multifilament superconducting wire with 42 filaments. The superconducting wire will be heat treated and analyzed as to their microstructure and superconducting properties.