Production of volume samples from melt textured high temperature superconducting material comprises molding powder into open vessel and applying seed crystal

摘要

Production of volume samples from melt textured high temperature superconducting (HTSL) material comprises molding powder into open vessel and applying seed crystal. Producing volume samples comprises: (a) powder metallurgically preparing the volume probes from a powder or powder mixture suitable for a melt texture; and (b) melt texturing with required orientation using seed crystals to achieve and adjust the required characteristic properties such as glass transition temperature Tc and critical current density jc. Before the first cooling phase or during the first cooling phase for each volume region of the high temperature superconducting body for which on its surfaces away from the microwaves an X-ray diffraction pattern of required alignment is produced. The powder is molded into an open vessel mold onto which a seed crystal is placed. The seed crystal has a higher decomposition temperature than the maximum temperature (Tmax) arising at the melt X-ray diffraction pattern or the temperature selected at or during the first cooling phase on the highest lying point of the volume region with corresponding alignment of is c-axis, from which the X-ray diffraction pattern extends in the volume region below. The surfaces facing the microwaves are subjected to surface fine treatment to attain the prescribed microwave surface resistance after melt texturing.