High trapped field performances in thin-wall YBa₂Cu₃O_7−δ bulk cryomagnets Available to Purchase

Thin-wall YBa₂Cu₃O_7−δ bulk single domains were grown from drilled preforms with a holes network in the aim of increasing the specific areas and diminishing the oxygen diffusion paths. By applying a progressive annealing at high temperature under oxygen pressure (10 MPa), crack-free superconductors were obtained in a very short time (less than 3 days). A crack-free microstructure fostered large size persistent current loops, which boosted the trapped field performances. A trapped field B_max = 5.2 T at 17 K was achieved on a 16 mm-diameter thin-wall pellet (disk surface s = 1.987 cm²), which led to a striking trapped field density $BmaxS=2.617 T cm−2$⁠.