Editing Iron(III) oxide (section)

===Gamma phase===
[[maghemite|γ-Fe<sub>2</sub>O<sub>3</sub>]] has a [[cubic crystal system|cubic]] structure. It is metastable and converted from the alpha phase at high temperatures. It occurs naturally as the mineral [[maghemite]]. It is [[ferromagnetic]] and finds application in recording tapes,<ref name="InorgChem"/> although [[ultrafine particles]] smaller than 10 nanometers are [[superparamagnetic]]. It can be prepared by thermal dehydratation of gamma [[iron(III) oxide-hydroxide]]. Another method involves the careful oxidation of [[iron(II,III) oxide]] (Fe<sub>3</sub>O<sub>4</sub>).<ref name="InorgChem"/> The ultrafine particles can be prepared by thermal decomposition of [[iron(III) oxalate]].