Thin films in the Bi‐Sr‐Ca‐Cu‐O system have been synthesized from liquid ethyl hexanoate precursors by spin pyrolysis. An extensive solid solution range was determined for the two Cu‐layer phase through the study of c‐axis oriented, single‐phase thin films fabricated on single‐crystal MgO (100). Extensive cation non‐stoichiometry was observed in all cases. The variation of important thin film properties with composition within the solid solution range have been described.
Utilising the results from the thin film study together with data relating to liquid formation in mixtures of bulk material a working model describing the formation of the two‐layer phase has been formulated. The two‐layer phase is formed as the result of precipitation from a fugitive liquid at temperatures exceeding 730 *C.