FeMgAl

FeMgAl is a shorthand designation used in materials science and mineralogy to describe systems where iron (Fe), magnesium (Mg), and aluminum (Al) are the principal elements. It does not refer to a single chemical compound, but to a ternary composition that can exist in different phases, most commonly as oxides or intermetallics. The term highlights the combined presence of the three metals and the potential for extensive solid-solution among them.

In geology and mineralogy, Fe, Mg, and Al can occupy multiple crystal-chemistry configurations within solid solutions. Garnet and spinel families are typical examples where Fe and Mg substitute for each other and Al occupies specific lattice sites, producing a range of endmember compositions such as garnet (Fe, Mg)3Al2Si3O12 or spinel-like (Mg,Fe)(Al,Fe)2O4. These minerals provide insight into metamorphic and igneous processes and are often used as geothermometers and geobarometers.

Magnesium aluminum spinel, MgAl2O4, represents a common binary oxide within the broader Fe–Mg–Al system and serves as a well-studied reference phase for cation distribution and high-temperature stability. Iron-containing spinels and aluminates are used in ferrimagnetic ceramics, pigments, and refractory materials, with Mg as a dopant to tailor properties.

In metallurgy and ceramics, FeAl-based intermetallics and related alloys with Mg additions are investigated for oxidation resistance and high-temperature performance. Processing methods include solid-state synthesis, sintering, and advanced ceramic routes; achieving uniform Fe–Mg–Al distribution is a key challenge for reliable properties.

Overall, the FeMgAl system encompasses a diverse set of phases and applications, reflecting the complex phase relations and functional potential of these three abundant elements.