Effect of plastic deformation on the electrophysical properties and structure of YBa2Cu3O y ceramics subjected to low-temperature treatment

Abstract

The electrophysical properties and structure of HTSC YBa2Cu3Oy compound (123) subjected to plastic deformation by shear under a pressure of 1.7 GPa have been studied. After deformation, the electrophysical properties of samples prepared using the traditional ceramic technology were found to deteriorate. Subsequent annealing at 930°C cannot restore the critical current density (jc) in low magnetic fields to initial magnitudes; however, in magnetic fields of more than 0.1 T, the jc magnitude increases compared to that for the starting state. The deformation of 123 ceramics treated at 200°C in a humid atmosphere that has undergone phase transformation into the 124 tetragonal phase allows its structure and electrophysical properties to be restored. In this case, the reverse transformation of phase 124 into 123, which is accompanied by the recrystallization of the material, takes place. The combination of low-temperature treatment and high shearing deformation leads to the appearance of texture and an increase of jc, in particular in high magnetic fields.