A review on the synthesis of Y–Ba–Cu-oxide powder

Abstract

The preparation of Y–Ba–Cu-oxide (YBCO) powder by various techniques is critically reviewed and the synthesis of ultrafine superconducting YBa2Cu3Ox(123) powders is specially emphasized. The fine powder has assumed a large importance, requiring the minimization of processing parameters (time and temperature) during calcination, homogenization and sintering to avoid the problems of evaporation of the constituent oxides. From the voluminous research activities on YBCO it is known that by adopting any preparation technique the superconducting transition temperature (Tc) value of ≈92 K could be achieved in the bulk samples, thus in this review the Tc values are not emphasized. Also, the other transport properties such as critical current densities (Jc) and magnetic properties are not discussed, since these properties are mainly controlled by many other parameters related to the weak link across the grain boundaries of the specimens, and a very little role is played by the synthetic procedure. The weak links across the grain boundaries are known to be the cause for the poor Jc values in bulk specimens and those weak links are observed due to the presence of impurities at the grain boundaries, misorientation of grains and oxygenation of the samples. By selecting the proper synthetic procedure, only the impurity problem can be solved, and to remove the other problems, a proper fabrication method needs to be adopted. This review will guide the new researcher to find the appropriate technique to synthesize good quality YBCO powder.

Modified Pechini Synthesis of Oxide Powders and Thin Films

“…There are numerous reports on different synthesis routes to prepare YBCO powder, as reviewed by Kakihana and Pathak and Misra (Kakihana 1996;Pathak and Mishra 2005). The powder characteristics, like homogeneity, phase-purity and particle size, will have a large influence on the properties of the final device, and both solid-state (Cava et al 1987) and wet chemical synthesis routes (Kamat et al 1991), have been employed for the synthesis of YBCO.…”

Theoretical investigation of geometric configurations and vibrational spectra in citric acid complexes

“…A deeper understanding of complexes between α-hydroxycarboxylic acids and metals (M) that are formed on those routes is desirable, since these compounds are highly effective in obtaining heterometallic advanced ceramics 1 . Several metallic ions with different applications have been employed in this kind of route, such as lithium ion in the manufacturing of cathodes for fuel cells 2,3 and barium ion in pellets of high temperature superconductors [4][5][6] , magnetic materials 7,8 , and multiferroic materials 9 . The modified polymeric precursors method (MPPM) 1,4 involves the polyesterification process of a metal chelate complex using a hydroxycarboxylic acid and a polyhydroxy alcohol in an aqueous solution, which turns into a polymeric gel.…”

“…*e-mail: lavarda@fc.unesp.br Theoretical Investigation of Geometric Configurations and Vibrational Spectra in Citric Acid Complexes Although it is a widely used synthesis route, intermediate physicochemical reactions and metal complexes are still poorly known 6 , having been the subject of only a small number of theoretical works [10][11][12] .…”

Hydrolysis of a (2‐Propanol)yttrium Triiodide Complex in the Presence of Glymes: Synthesis and X‐ray Structures of Hydroxo‐Bridged Dinuclear Yttrium Complexes and Their Applications in Materials Science

“…[29] The Y···Y distances [3.684 (1) Iodides of yttrium, barium, and copper have been shown to be among the most attractive precursors for the formation of YBCO, since they do not form stable BaCO 3 during the decomposition. [1,30] However, formation of ionic Y-Cu clusters was recently reported by us from an all-iodide solution in DMF and 2-isopropoxyethanol. [23] This results in an inhomogeneous solution, which is inappropriate for MOD.…”