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

International audienceThe progress of the melt growth synthesis technique for preparing superconducting REBaCuO bulks allows the production and commercialization of a single crystal with a diameter of 10 cm. This is in good agreement with the development of new applications such as electrical motors where superconducting bulks are used as trapped field magnets or magnetic shields [1], [2]. It is then crucial to determine the superconducting properties such as the critical temperature, critical current density and irreversible magnetic field which is commonly done with the help of an MPMS-SQUID on a millimeter-size sample. However, the inhomogeneity of performances has been reported on a bulk [3], which highlights the necessity to measure the critical properties in multiple positions along the sample radius either in a grain sector or along a grain sector boundary.We propose a similar work with a characterization carried out on a 10 cm wide commercial bulk after machining for use as magnetic shields [1]. 24 rectangular samples have been extracted in a different position from the bulk’s center, prepared and measured on a 14 T MPMS with a VSM head. Then a comparison of the superconducting properties of each sample will be presented along with trapped field measurement done on 10 others wide GdBaCuO bulks. Finally, this will allow a discussion on the readiness of this technology and its possible future development and it will point out the necessity to measure the superconducting properties in different positions.[1]R. Dorget et al., « Design of a 500 kW partially superconducting flux modulation machine for aircraft propulsion », J. Phys. Conf. Ser., july 2021.[2]R. Dorget et al., « Review on the Use of Superconducting Bulks for Magnetic Screening in Electrical Machines for Aircraft Applications », Materials, jan. 2021.[3]V. Antal et al., « Relationship between local microstructure and superconducting properties of commercial YBa2Cu3O7- δ bulk », Supercond. Sci. Technol., févr. 2020