metaloxygen

Metaloxygen is not a widely recognized term in chemistry. In practice, compounds composed of metal and oxygen are called metal oxides or, in specific classes, metal peroxides and superoxides. The phrase may be used informally to refer to the broader family of metal-oxygen compounds, which span many elements and structures.

Most metal-oxygen bonds are highly ionic, especially for early transition and main-group metals, yielding oxides with crystalline lattices such as rutile, corundum, spinel, or perovskite. The oxidation state of the metal is typically matched by the oxide's stoichiometry (e.g., Fe2O3, TiO2, Al2O3). Some compounds exhibit covalent character and complex structures.

Synthesis methods include direct oxidation of metal, solid-state reactions between metal oxides, hydrothermal or solvothermal synthesis, chemical vapor deposition for thin films, and precipitation from metal salts. Many oxides are thermally stable, while others form at lower temperatures via hydration or carburization.

Properties of metal-oxygen compounds include high melting points and hardness for many oxides; they are often insulating, with some being semiconductors or ferrimagnetic (e.g., magnetite Fe3O4, ferrites). They can function as pigments, catalysts, ceramics, insulators, or electrolytes in energy devices.

Applications span catalysis (oxidation, dehydration), pigments for ceramics and paints, electronics (dielectrics and transparent conducting oxides), batteries and solid oxide fuel cells, and photocatalysis (TiO2).

Examples include Fe2O3 (hematite), Fe3O4 (magnetite), Al2O3 (alumina), TiO2 (titanium dioxide), ZnO, SnO2, and perovskites such as SrTiO3. See also metal oxide.