AAO3

AAO3 is not a standard, widely recognized chemical formula in inorganic chemistry. In many contexts, it appears as a nonstandard shorthand for the stoichiometry A2O3, describing oxides of trivalent elements. The conventional representation is A2O3 in which two atoms of a metal with oxidation state +3 combine with three oxide ions.

Examples of A2O3 compounds include aluminum oxide Al2O3, iron(III) oxide Fe2O3, chromium(III) oxide Cr2O3, and bismuth(III) oxide Bi2O3. These materials span ceramic and pigment applications and often crystallize in robust, high-melting-point structures such as corundum-type Al2O3 or hematite-type Fe2O3.

Preparation methods vary: direct oxidation of the metal at elevated temperature, precipitation and calcination from metal salts, or solid-state reactions between metal oxides. The exact route depends on the specific element and desired phase.

Properties common to many A2O3 compounds include high thermal stability, high hardness for some materials, and insulating electrical behavior. Crystal structure depends on the metal; corundum (alpha-Al2O3) is a famous form, while other M2O3 polymorphs exist.

Uses for A2O3-type materials encompass abrasives, catalysts, refractory ceramics, and pigments. Safety considerations for oxide dusts apply; inhalation can irritate the respiratory system, and standard laboratory precautions should be observed.

Note that the formula AAO3 is nonstandard. When referring to these compounds, the conventional notation A2O3 is preferred, with the identity of A specified to avoid ambiguity.