Method and apparatus for inducing grain orientation by magnetic and electric field ordering during bulk superconductor synthesis

摘要

A process is described for enhancing superconductor characteristics by application of strong magnetic and/or electric fields to the constituent component materials from which ceramic superconductors are being formed and during the time that these superconductors are being synthesized. This process has particular applicability to the production of superconducting oxide ceramics such as the cuprates. The required magnetic fields are on the order of 1-10 tesla and the required electric fields are on the order of 0.1-1 MV/cm. The fields act as ordering mechanisms and induce grain orientation. The magnetic field aligns the magnetic moment of the grains. The electric field induces electric polarization in the grains and then aligns them. The superconducting structure formation occurs during the sintering, cooling and annealing phases of the fabrication process. Superconductivity is strongly affected by the oxygen stoichiometry in the lattice elemental cell. Applied electric fields cause elongation of the unit cell. This accelerates oxygen diffusion throughout the lattice and this gives better control of the oxygen content of the sample. Applied magnetic fields exert a magnetic pressure on the sample. This invention produces ceramic superconducting materials with a high degree of grain orientation and current density properties equivalent to or exceeding many of the existing superconducting materials.