Comparison of Mechanical and Superconducting Properties of YBaCuO and GdBaCuO Single Grains Prepared by Top-Seeded Melt Growth

Abstract

It is known that mechanical properties of a high-temperature superconductor (HTS) can affect the superconducting behaviour of the material. In this study, the mechanical and basic superconducting properties of single-domain YBaCuO and GdBaCuO were determined and compared. The bulk single-grain superconductor samples were prepared by top-seeded melt growth process. Distribution of trapped fields in the samples was mapped using the Hall probe technique. Levitation force was assessed using a dynamometer. Phase composition of the samples, was characterised by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) measurements. Microstructure was studied using scanning electron microscopy (SEM) and optical microscopy. Microhardness and comprehensive strength of the prepared samples were measured at a room temperature. The GdBaCuO superconductor has shown higher average hardness than the YBCO sample; higher fragility was also observed by comprehensive strength measurement of both types. Maximum trapped magnetic field was 0.65 T at 77 K in the case of a Gd-based material. In comparison with YBaCuO, the values of the trapped magnetic field and levitation force of GdBaCuO were higher. The results obtained can be useful for rare earth element (RE) superconductor device engineering as well as for the research in the field of superconducting ceramics.