Introduction: Inorganic electrochemistry

Three Perovskite Phases with Different Cation Orders in Sm2MnMn(Mn4−xSbx)O12

“…Perovskites are noteworthy in their ability to take a wide range of cations on the A and B sites resulting in a variety of practically important properties such as catalytic, ferroelectric, ferromagnetic, and superconductive [1–4] . Cations in both A and B sites of perovskite oxides can order in three types: layered, columnar, and rock‐salt arrangements [5,6] . B‐site orders in perovskites, driven by oxidation state differences, have most examples, [7,8] including double, triple, and quadruple perovskites, A 2 BB′O 6 , A 3 BB′ 2 O 9 , and A 4 BB′ 3 O 12 .…”

“…[1][2][3][4] Cations in both A and B sites of perovskite oxides can order in three types: layered, columnar, and rock-salt arrangements. [5,6] B-site orders in perovskites, driven by oxidation state differences, have most examples, [7,8] including double, triple, and quadruple perovskites, A 2 BB'O 6 , A 3 BB' 2 O 9 , and A 4 BB' 3 O 12 . Quadruple perovskites with AA' 3 B 4 O 12 and A 2 A'A''B 4 O 12 compositions are common in Asite-ordered structures while A-site-ordered AA'B 2 O 6 double perovskites are much rarer and usually realized together with simultaneous 1 : 1 cation orders at both A and B sites; they are called doubly ordered (or double double) perovskites, AA'BB'O 6 .…”

“…[11,13,14] Properties of perovskite-type materials can be modified through cation order, which in turn can be controlled by different synthesis conditions and different stoichiometries especially utilizing differences in oxidation states, ionic radii, and electronic structures of cations. [5] For example, there is a dramatic switch of magnetic properties from ferromagnetic order with full magnetization of 5μ B in cation-ordered R 2 NiMnO 6 (R = rare earth elements) to spin glass behaviour with noticeably reduced magnetization in cation-disordered R 2 NiMnO 6 . [15,16] In LaBaMn 2 O 6 with colossal magnetoresistance, the Curie temperature increases from 270 K in a disordered phase to 335 K for a cation-ordered phase.…”