Critical current density function of the position in a commercial REBaCuO bulk

International audienceAdvances in the melt-growth synthesis technique for preparing superconducting REBaCuO bulks allow the production and commercialisation of single crystals with a diameter of about 10 cm. This is in close agreement with the development of new applications such as electric motors where superconducting bulks are used as trapped field magnets or magnetic screens [1], [2]. It is then crucial to determine the superconducting properties such as critical temperature, critical current density and irreversible magnetic field, which is usually done using MPMS-SQUID on a millimetre size sample. In this study, the characterisation of a 10 cm wide commercial bulk machined for use as a magnetic shield is presented, see Fig. 1. 24 orthorhombic samples were extracted at different positions from the centre of the bulk, prepared and measured on a 14 T MPMS with a VSM head. A comparison of the superconducting properties of each sample will be presented together with the trapped field measurements performed on 10 other wide REBaCuO bulks. This will provide an opportunity to discuss the state of the art of this technology and its possible future development and will highlight the need to measure superconducting properties in different positions. Fig. 1: Magnetic flux density map measured on the surface of a REBaCuO bulk after magnetisation under 300 mT using a permanent magnet. References [1] Dorget, R. et al. Design of a 500 kW partially superconducting flux modulation machine for aircraft propulsion