Beschreibung:
<jats:p>Needle‐shaped spinel precipitates in a matrix of heavily MgO‐doped α‐AI<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> bicrystal containing a near Σ= 11 tilt boundary were examined by spatially resolved electron energy‐loss spectroscopy. The Mg content was consistent with the precipitate being an alumina‐rich spinel of composition MgO Σ(Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>. The Al and Mg <jats:italic>K</jats:italic> and <jats:italic>L</jats:italic><jats:sub>2.3</jats:sub> absorption edge structures were recorded. No evidence could be found for preferential Mg segregation to the tilt boundary. Using the precipitates as a calibration standard, a limit of detection equivalent to about 0.01 monolayer is deduced. Comparison of the Al‐<jats:italic>L</jats:italic><jats:sub>2.3</jats:sub> edge recorded at the Σ= 11 boundary to that of the same boundary in undoped material suggests that the local structure is independent of Mg doping. The lack of Mg segregation to the Σ= 11 boundary is perhaps attributable to the low energy and close packing of this interface.</jats:p>