The cation‐atom distribution in a (Cr, Fe, Al, Mg) 3 O 4 spinel as revealed from the channelling effect in electron‐induced X‐ray emission

The anomalous production of X‐rays which occurs when an electron beam is incident on a thin crystal under certain crystallographic directions has been used to study the site occupancy in a chromite from the Stillwater Complex, Montana with approximate composition (Cr 0.37 Fe 0.23 Al 0.23 Mg 0.17 ) 3 O 4 . Cr and Al are found to have a strong octahedral and Mg a strong tetrahedral site preference. About 3/4 of the Fe atoms are on tetrahedral sites. Small amounts of Ti and V atoms, about 1/1000 of the total atomic content, are both found to occupy the octahedral sites.