Silver solubility in YBa 2Cu 3O x

Abstract

Ceramic YBa 2Cu 3O x samples with different amounts of nominaly added silver (0.5; 1.0; 1.5; 2.5; 5 and 10 wt.%) have been studied using X-ray diffraction, SEM, EDS and WDS techniques. Silver appears to be present within the grains. The Ag concentration increases with the nominally added Ag then saturates at the nominal Ag concentrations >2.5 wt.%. The solid solubility of silver in YBa 2Cu 3O x sintered in the air at 950°C for 24 h then annealed in oxygen at 500°C for 24 h, has a saturation level, ∼ 0.37 wt.% at room temperature, and the corresponding y value is 0.023 of YBa 2Cu 3− y Ag y O x . The lattice parameters of the orthorhombic unit cell, a and c, are found to increase with increasing Ag concentration, whereas the lattice parameter b remains the same for all the samples with different Ag contents and has the value of the pure YBa 2Cu 3O x specimen. The noticeable changes in the a and c lattice parameters were linked with Ag substitution for Cu in Yba 2Cu 3O ceramics.