ChemInform Abstract: SUBSOLIDUS‐ZUSTANDSDIAGRAMM DES SYSTEMS AL2O3‐CR2O3‐P2O5

Abstract

Im System Al2O3‐Cr,O3‐P2O5 werden röntgenographisch die binären Phasen (I)‐(III) nachgewiesen und das Zustandsdiagramm konstruiert.

An Extended In Situ Cu−K XAFS and XRD Study on the Site Preference and Valence of Copper Ions in (Mg1-xCux)O

“…The phase boundary separating the single-phase field of (Mg 1 - x Cu x )O from the two-phase field was confirmed by thermogravimetric investigations 1 Part of the Mg−Cu−O phase diagram: composition x versus oxygen activity a O 2 at the magnesium rich side ( T = 1373 K): ▾ 3 ; ∇ 14 ; ▪; □ …”

“…In the late 40s, the MgO derivate copper-doped magnesium oxide, (Mg 1 - x Cu x )O, was synthesized and structurally characterized by Rigamonti, and quenched specimens were tested with respect to their catalytic activity 8,9 and optical properties , ), and according to the x − T phase diagram, − the magnesium-rich phase ( x < 0.20) is stable over a wide range of temperature and composition. Although structurally rather simple (both sublattices are cubic face centered), the local environment and valence of the copper dopant might differ from those of the matrix ions, and its nature is still unknown: The valence of copper may vary between +1 and the unusual valence state +3. − The dopant may substitute magnesium or be distributed within the interstitial sublattice depending on the experimental conditions. , The existence of a Jahn−Teller distortion around Cu[Ar] d 8 and Cu[Ar] d 9 is also possible at low temperatures ( T < 300 K) and is controversially discussed in the literature. ,,− , …”

“…Part of the Mg−Cu−O phase diagram: composition x versus oxygen activity a O 2 at the magnesium rich side ( T = 1373 K): ▾ 3 ; ∇ 14 ; ▪; □ …”

“…11 (Mg 1-x Cu x )O crystallizes in the rock salt structure (a ) 421. .31 pm at T ) 293 K and x e 0.1 12,13 ), and according to the x-T phase diagram, [14][15][16] the magnesium-rich phase (x < 0.20) is stable over a wide range of temperature and composition. Although structurally rather simple (both sublattices are cubic face centered), the local environment and valence of the copper dopant might differ from those of the matrix ions, and its nature is still unknown: The valence of copper may vary between +1 and the unusual valence state +3.…”

“…Although structurally rather simple (both sublattices are cubic face centered), the local environment and valence of the copper dopant might differ from those of the matrix ions, and its nature is still unknown: The valence of copper may vary between +1 and the unusual valence state +3. [11][12][13][14][15][16][17][18][19][20] The dopant may substitute magnesium or be distributed within the interstitial sublattice depending on the experimental conditions. 3,21 The existence of a Jahn-Teller distortion around Cu[Ar]d 8 and Cu[Ar]d 9 is also possible at low temperatures (T < 300 K) and is controversially discussed in the literature.…”