Silver Addition and Zirconium Substitution in the YBa₂Cu₃O_7-xPrepared by Organic Acid Salt Thermal Decomposition Process

Abstract

The high-T c YBa2Cu3O7-x (123) superconductor has been synthesized through a decomposition of organic acid salts. T c's of 92 K have been obtained after a relatively short sintering in the 123 specimen. Effects of silver addition and zirconium substitution on superconducting properties and structures were studied. The Ag addition and the Zr substitution appreciably enhances the J c of sintered 123 specimen. The Ag addition decreases the optimum sintering temperature by about 50°C. The Zr substitution is found to significantly change the morphology of 123 grains.

Powder melting process for superconductor by eutectic formation

“…Ag is an important additive used in Y-Ba-Cu-O-based superconductors because it minimizes cracks created during the forming and sintering stages and lowers the melting temperature. In particular, addition of Ag can lower the melting temperature by as much as 50 • C and the sintering temperature by as much as 150 • C [12][13][14][15]. Also, Ag addition can, to some extent, reduce the problem of mechanical and electrical grain boundary weak links [16,17] through increased grain growth [18][19][20] and reduced contact resistance by filling of surface pores [21,22].…”

Synthesis of Composite Polycrystalline Ba₂YCu₃O_7-<i>y</i> Superconductor by the Sol-Gel Method

“…Sol-gel method is an effective method in the prepa ration of a bulk or powder with homogeneous distri bution of each element. So, this method has been ex pected to enhance the sinterability of a raw powder mixture.3)-8) Moreover, sol-gel method enables us to obtain composites with the complicated structure in nanometer order.9), 10) On this point of view, some kinds of composites High temperature X-ray diffraction patterns (Fig. 4) indicate the mixture of intermediate phase up to the density is 6.38g/cm3 for BYCO and 5.47g/cm3 for Ba2SiO4, respectively.…”