Magnesium dititanate (MgTi₂O₅) with pseudobrookite structure: a review

Magnesium dititanate (MgTi₂O₅, MT₂) has been synthesized since the early 1930s. It has the pseudobrookite structure (general formula Me₃O₅), corresponding to the Mg-enriched artificial endmember of the Fe₂TiO₅ (pseudobrookite)–FeTi₂O₅ (ferropseudobrookite)–Mg_0.5Fe_0.5Ti₂O₅ (armalcolite) solid solution. Since MgTi₂O₅ has relativity high thermal stability among pseudobrookite-type phases, it is expected to be a well-balanced low-thermal-expansion material. Here we review both the historical and recent studies on MgTi₂O₅, particularly on its crystal structure, cation order–disorder, physical properties and synthesis methods.