Importantly, layer by layer analysis of the EELS spectra (Figure ) taken from the perovskite layers demonstrates an increase in the value of Δ through the layers from outer layer to center layer. The average increase from the outer perovskite layer to the center perovskite layer is 0.13 ± 0.06 eV. Since this was collected within a single dataset, it implies that there is a change in the magnitude of the crystal-field splitting across the five-layered structure. This change in Δ through the layers was observed in two different sample pieces from different DLI-CVD growth runs and measured on different days with two different types of EELS detectors. The spatially resolved EELS spectra demonstrates that the position of the t2g peak position remains constant. Therefore, this change in Δ is due to a shift in the energy of the eg peak, which increases in energy moving from the outer to center perovskite layers. The fact that the t2g level does not change while the eg peak energy position shifts position signifies that this change in the energy levels is associated with a change in the crystal field splitting. Eleven EELS data sets were used to calculate the average Δ value, as shown in SI Table . Each data set had two eg values for the outer perovskite layer and one eg value for the center layer, therefore for each data set, two Δ values were obtained (twenty-two data sets were obtained in total as shown in SI Table ). The trend of increased Δ values towards the center layers was observed for all measurements. observed in the density of states of the eg energy level. Recent work , on (PbTiO3)n/(SrTiO3)n systems displaying polar vortices has shown changes to the Ti 3d orbital interactions and changes to crystal field as a function of position within the heterostructure. Given that B6TFMO could be regarded as a natural heterostructure of [Bi2O2] 2+ interlayers and Ti[Fe,Mn]O perovskites, in the following sections, we consider possible contributions to the changes we observe in the Ti L3 eg peaks as a function of position. This includes examination of tetragonal distortion differences and variations in tilting of the BO6 octahedra imposed by the [Bi2O2] 2+ interlayer.