화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.103, No.9, 5169-5177, 2020
Artificially perforated single-grain YBCO bulks: Dependence of superconducting properties on the bulk thickness
A high and homogenous trapped field, as well as the levitation force of YBCO parts are the key properties in regard to practical applications of high-temperature superconductors. Both of these parameters are often the determining factor in the bulk's performance. In this contribution, the impact of bulk thickness on the trapped field and levitation force was studied in detail. A number of significantly thicker samples both with and without artificial holes were prepared. The samples were manufactured using top-seeded melt growth with a diameter of 28 mm and a thickness of 18 mm. An additional source of "liquid phase" was placed underneath the YBCO bulks during the TSMG process in order to negate the leakage of "liquid phase." Properties of these samples were compared and to most similar samples with and without artificial holes were chosen to be gradually ground down. SEM was employed in order to confirm the impact of artificial holes on the microstructure. The samples were characterized between each individual grinding step. Using this approach, the dependency of the trapped field and levitation force, as well as the addition of artificial holes, can be properly evaluated. The method described above has allowed us to determine the optimal bulk geometries for various applications depending on the desired properties. Such data are of the utmost importance in the field of applied high-temperature superconducting bulks.