One step synthesis of Bi(Pb)-2223 phase in Bi(Pb)-Sr(Ba)-Ca-Cu nitrate freeze dried powder

Abstract

One step synthesis of the superconducting Bi(Pb)-2223 phase during heat treatment for non-equilibrium decomposition of the freeze dried Bi:Pb:Sr:Ba:Ca::0.4:1.8:0.2:2.2:3.0 nitrate powder has been studied. The heating rate was and samples were maintained in air at C for 0, 5, 10, 20, 30, 60, 90, 240 and 1080 min. Each batch was investigated by x-ray diffraction analysis and ac magnetic susceptibility . Evolution of phases and kinetics of phase formation-decomposition processes were discussed. % of Bi(Pb)-2223 has formed indicating the possibility of lowering the processing time of the freeze dried precursor powders by one order of magnitude comparative to the multistep synthesis route (from hundreds to tens of hours). A 30 min heat treatment step at C performed on the way up to the synthesis temperature is a forthcoming operation in order to block the formation of secondary undesired phases (e.g. .

Reactive-field-assisted-sintering of freeze-dried powders in the BSCCO system

“…conditions (i.e. high heating rates) [11]). This approach has resulted in a decrease of the synthesis and processing time of the superconducting 2223-powder by one order of magnitude (from hundreds to tens of hours).…”

“…Samples, decomposition and RFAST regime, and bulk density of the pellets after RFAST. favourable for the synthesis of 2223-phase in freeze-dried nitrate powder [11]. Electrical field sintering is a combination of on/off pulses and dc current application.…”