Preparation of 95 K Bi₂CaSr₂Cu₂O_8+δ Superconductor from Citrate Precursors

Abstract

Highly crystalline single phase “2122”, Bi2CaSr2Cu2O8+δ, sample with δ=0.25 has been prepared from citrate precursors with pyrolysis. Stable and bulk superconductivity with T c(onset)=99 K and T c(zero)=95 K was reproducibly detected by the magnetic susceptibility and electrical resistivity measurements, respectively.

Investigation of Structural Formation of Starting Composition 2245 in the Bi-Pb-Sr-Ca-Cu-O System Superconductors

“…The value of cuprate superconductors is known to vary with oxygen stoichiometry and is found to be a maximum for an optimum value of oxygen content. This can be manifested in terms of partial change of the valence state of copper from Cu 2+ to Cu 3+ in the Bi system superconductors [13][14][15][16].…”

Preparation of Bismuth- and Thallium-Based Cuprate Superconductors

“…The nitrates can also be precipitated from solution in the form of t-e citrate salts (42). This also leads to intimate mixing and eliminates the need for a spray drying apparatus.…”

Study of the structure and optical properties of rare-earth-doped aluminate particles prepared by an amorphous citrate sol–gel process

“…It had been an efficient technique for the preparation of phosphors due to good mixing of the starting reagents and relatively low reaction temperature, which resulted in more homogenous products than those obtained by direct solid-state reactions. The typical sol-gel processes based on polymeric precursor methods are the amorphous citrate and Pechini processes [8][9][10][11][12]. In the amorphous citrate process, citric acid is generally used as the chelating agent of the metal cations, while in the Pechini process, a hydroxycarboxylic acid and poly-hydroxyl alcohol are used together to obtain a resin impregnated with the ions.…”