“…These parameters conrm that the renements are acceptable and the samples compositions are the same as their nominal compositions, including that the oxygen content was close to 3 for all the samples. 22 The three equivalent positions (6a (0, 0, 1/4), 6b (0, 0, 0), and 18e (x, 0, 1/4)) in the rhombohedral unit cell are occupied by 6a (La 3+ , Pr 3+ , Ba 2+ ), 6b (Mn 3+ , Mn 4+ ), and 18e O 2À respectively. Table 1, where a and c are the hexagonal cell parameters, V is the unit cell volume, B iso is the isotropic thermal parameter, q (Mn-O-Mn) is the bond angle, d MnÀO is the bond length and x is the oxygen position.…”