Le diagramme des phases solides du systeme Bi2O3CaO

New Bi–Ln–V–O Anionic Conductors withδ-Bi2O3Fluorite-Type Structure (Ln=Y, Sm, Eu, Gd, Tb, Dy, Er, Yb)

“…However, the ''stabilization'' strongly depends on the cooling conditions of the samples from the equilibrium domain. For example, the structure is not observed at room temperature in both Bi O -CaO and Bi O -PbO systems when the samples are air-quenched in alumina crucibles (15,16). However, only for the Bi O -CaO system, is easily preserved when the samples are air-cooled down in gold crucibles.…”

An Electron Diffraction and XRD Study of the α′1 and α″1 Fluorite-Related Phases in the (1−x)12Bi2O3·xCaO, 0.20<x<0.29, System

“…A face centered cubic (fcc), -type solid solution phase was reported to exist at elevated temperatures all the way up to a maximum CaO content of &29 mol%. Con#ant et al (5), however, also reported the existence of a small region in the CaO-rich, low-temperature portion of this fcc phase "eld which di!ered from a purely cubic disordered fcc structure. In particular, weak (slightly composition-dependent) superstructure re#ections were reported as accompanying the strong Bragg re#ections of an underlying fcc average structure for x greater than 25 mol% CaO.…”

“…The equilibrium phase diagram for this system was "rst published by Con#ant et al (5) and subsequently modi"ed somewhat by Roth and colleagues (12,13). A face centered cubic (fcc), -type solid solution phase was reported to exist at elevated temperatures all the way up to a maximum CaO content of &29 mol%.…”

“…One such ternary bismuth oxide phase is the so-called -type solid solution phase in the (1!x) Bi O ) xMO, M"Ca, system (4,5,12,13). The equilibrium phase diagram for this system was "rst published by Con#ant et al (5) and subsequently modi"ed somewhat by Roth and colleagues (12,13).…”

“…Much work has been devoted over a considerable period of time to the remarkable structural #exibility and oxygen ion transport properties of many such ternary bismuth oxide phases (3}11). In the form of higher temperature solid solution phases, such phases are frequently highly conductive but often undergo phase transitions into related lower temperature phases upon cooling at which desirable transport properties can change signi"cantly (5,10).…”