“…41 Refinements of the Al occupancies (Table 3) indicated that Fe ions occupied the symmetric tetrahedral Al(2) sites in the spinel block and the distorted tetrahedral interstitial Al(5) sites in the mirror plane with occupancy of 20.2% and 6.0%, respectively, similar to the distribution of Fe in BF1A-1200 (20.1% and 6.5%). 22,23 In contrast to Fe, Ir ions only occupied the tetrahedral interstitial Al(5) sites in the mirror plane, while Al(1), Al(2), Al(3), and Al(4) sites did not show any significant evidence of Ir substitution.…”