Sintering behaviour of La1−xSrxFeO3−δ mixed conductors

De‐densification mechanisms of yttria‐doped cerium oxide during sintering in a reducing atmosphere

“…In some cases, however, swelling can occur to result in the destruction of the ceramic. Such de-densification phenomena (or de-sintering) have been observed in many materials such as ZnO, 1,2 Fe 2 O 3 , 3 superconductors, 4 some carbides and nitrides, 5,6 nuclear fuels, [7][8][9][10][11][12][13][14] ITO, 15 (LaSr)FeO 3 , [16][17][18] and BaTiO 3 19-25 ceramics.…”

“…More recent work only highlights the role of the decomposition of the remaining BaCO 3 . Swelling in LaFeO 3 ‐type ceramics was attributed to phase equilibria that led to oxygen gas releases and pore expansion, together with the presence of a liquid phase that also promoted exaggerated grain growth . The role of additives should also be taken into account: dopant redistribution during sintering can induce de‐densification due to a change in oxidation state and interfacial chemistry .…”

“…23 Swelling in LaFeO 3 -type ceramics was attributed to phase equilibria that led to oxygen gas releases and pore expansion, together with the presence of a liquid phase that also promoted exaggerated grain growth. [16][17][18] The role of additives should also be taken into account: dopant redistribution during sintering can induce de-densification due to a change in oxidation state and interfacial chemistry. 32 In the same manner, when cobalt is used as a sintering aid in (Bi 0.5 Na 0.5 )TiO 3 piezoelectric ceramics, its valence state changes during heating to produce O 2 releases.…”

Electrode Properties of Pr0.7Sr0.3Fe0.8Al0.2O3-δ Thin Film Prepared by Pulsed Laser Deposition

“…As sintering temperature exceeds 1180 o C, the formation of secondary phases (see an SEM image in Figure 2 and decrease in relative density were observed. Sagdahl et al reported that La 1-x Sr x FeO 3-δ (LSF) having similar composition and structure to PSFA shows a low relative density after sintering at elevated temperature because of extensive swelling (6). The swelling takes place in the final stage of densification; the driving force of large pore formation seems to be O 2 evolution due to cation reduction; it is well know that LSF shows a large oxygen deficiency at elevated temperatures (7).…”

Peculiarities of layered perovskite-related GdSrFeO4 compound solid state synthesis

“…Obtaining of complex oxides with perovskite-related structure, including layered perovskite-related compounds, is conjugated with number of synthetic problems [1][2][3][4][5][6][7][8][9][10]. Mentioned previously difficulties are connected with thermal instability and multi-staged formation character of many from considered oxides [11][12][13][14][15][16][17].…”