The equiatomic composition of FeNi with the L1₀ structure is a potential candidate for rare earth-free permanent magnets. The L1₀ phase is only found naturally in meteorites that have cooled over billions of years. Producing this phase in a laboratory setting poses significant challenges due to the extremely low atomic mobilities of Fe and Ni below the critical temperature. The significantly low intensity of the superlattice diffraction peaks and negligible change in the c/a ratio during the ordering process makes detecting the L1₀ phase arduous. Soft X-ray diffraction fails to reveal superlattice peaks, but weak spots are observable in diffraction patterns in the Transmission Electron Microscope (TEM). If the superlattice peaks could also be observed by electron diffraction in the Scanning Electron Microscope (SEM), it would overcome the limitations of the small volumes available for investigation in the TEM and the complexities of preparing electron transparent lamellae from bulk materials.

The present work investigates a novel approach for detecting the L1₀ phase on a local scale by analysing average band profiles extracted from Electron Backscatter Diffraction (EBSD) patterns to reveal the presence of superlattice peaks. Superlattice peaks exhibit greater intensity in MnAl, establishing it as an ideal test system for the development of the method. EBSD patterns have been simulated for MnAl crystals with varying degrees of chemical order, and the resulting average band profiles have been compared with those extracted from experimental patterns. Various possibilities for detecting chemical order and estimating the degree of order will be discussed.