Real structure of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} prepared from various starting materials

The authors earlier studies showed that the physico-chemical nature of the starting reagents used in synthesis of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} has a strong effect on phase formation in the Bi-Sr-Ca-Cu-O system, so that the resultant compound may be formed by different mechanism and at different rates. Taking into account the pronounced {open_quotes}inertness{close_quotes} of the real structure of bismuth-based superconducting materials and the pronounced effect that phase-formation processes have on the real structure, the authors expect that high-T{sub c} materials of composition Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} prepared from different starting mixtures will differ in their structure-sensitive properties. In addition, the {open_quotes}inertness{close_quotes} of the bismuth-containing systems in responsible for the low reproducibility of their properties: minor variations in synthesis conditions may alter the mechanism for formation of the high-T{sub c} phase and, consequently, may yield materials that differ in real structure and related properties. Therefore, the purpose of this work was to study the real structure of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} materials prepared from reaction mixtures containing different cuprates as starting reagents.