Nonstoichiometry in oxides and its control

Analysis of oxygen potential of (U0.7Pu0.3)O2±x and (U0.8Pu0.2)O2±x based on point defect chemistry

“…Recently Karen [15] methodically outlined a point-defect scheme for description of non-stoichiometry in extended structures of oxides, and he calculated oxygen-content using experimental data. Sasaki and Maeir [16] numerically calculated defect concentration and estimated standard enthalpy and mass action constant.…”

Orbital occupancy evolution across spin- and charge-ordering transitions in YBaFe 2 O 5

“…The master sample was synthesized from a liquid-mixed citrate precursor [11], calcined and sintered in two batches in flowing gas atmosphere of controlled [22] partial pressure of oxygen at conditions listed in Table 1. The pellets of ∼20% porosity were used for quenching [11,22] from high-temperature equilibrium at 1000°C in flowing atmospheres of O 2 partial pressures set in the interval p −15.66 < log( /bar) < −14.10 O 2 to obtain YBaFe O w 2 5+ of low nonstoichiometry w or a product reduced to metallic Fe. Since YBaFe O w 2 5+ is in equilibrium with metallic Fe, the minimum-nonstoichiometry samples were also obtained by annealing with an excess of iron foil (99.5%, Goodfellow, 25 µm) in sealed evacuated silica ampoules at 450°C.…”

Temperature dependant X-ray diffraction study of PrSr3Co1.5Fe1.5O10–d ; n = 3 Ruddlesden-Popper phase

“…The oxygen annealed samples were heated in air to 1273 K, left to dwell for 1 h and then cooled to 373 K. This heating-cooling cycle was repeated twice so as to evaluate reversibility upon various heating/cooling cycles. Oxygen analysis was done by a modified cerimetric titration method as described by Karen [10].…”