Classification of perovskite and other ABO3-type compounds

Abstract

A classification of A +2 B+'03 com pounds has been made on t he basis of ionic radii of the cons tituent ions. A grap h of t his type for t he perovski te compounds can be ~ivide d in~o orthor hombic, pseud ocubic, a nd cubic fi elds, wit h an area of ferroelectn c and antlferroelectnc compounds s uperimposed on the cuhic fi eld . The structures of s ohd solutIOns . be~ween vari ous perov s ki te compou nds cannot b e completely c<;)JT el~ted on the basIs <?f thIs sImple two-dim e nsional chart. Therefore, a n ew type of classIficatIOn of t he perovsklte-type compounds has b een attempted, using a t hree-dimensiona l graph with pol ari~ab ili ty of ions plotted as tile t hird dimension. This t hree-dimensional grap h h a s been applJed s uc cessfully to comp ounds of t he type A+2BH 0 3, w hich crystalli ze with perovski te-ty pe structures. In addi tion a classifi cation of d ouble oxides of t ri valent ions has s hown that all co mpou nds of this typ~ having the pcrovs ki te s tructw·e can be divided into two groups, with rhombohedra l a nd orthorhombic sy mm etry. No ideal cubi c perovski tes of the A+3B+3 0 3 compounds have been found .

Crystallographic study of cerium aluminate (CeAlO3)

“…However, the synthesis of the compound in chemically homogeneous form has been unsuccessful by the usual methods because of the chemical instability of cerium trioxide. The crystal structure of CeAIO3 has been determined by other investigators (Roth, 1957;Schneider, Roth & Waring, 1961); it is rhombohedral, space group R-3m, and similar to that of certain other rare earth aluminates, REA103, investigated by Geller & Bala (1956). In the work of the former authors a second phase CeO was found to be present when CeA103 was prepared in helium atmosphere.…”

Chemical research needed to improve high-temperature processing of advanced ceramic materials (Technical report)

“…Muller and Roy recommended systematic, science-based guidelines that one should follow in search for new compounds with particular properties, and they illustrated the approach with several examples [12]. In this respect, the classification of groups of compounds with particular crystal structures, according to the constituent ionic radii ("structure field maps") is of particular value [13,14].…”

“…Of particular value are studies of systematic trends for a sequence of elements in the periodic table, thus enabling more reliable predictions of chemical reactions and properties for ceramic systems involved in manufacture when no data are available [13,14].…”

Perovskites: transforming photovoltaics, a mini-review

“…36 It is known from the first-principles study that the replacement of an inorganic A cation in a basic cubic perovskite structure by a suitable organic cation provides a material of a superior scope with a broad selection of properties. 37 In the early 1990s, an IBM researcher, David B. Mitzi, explored the structure-property relationship in organic-inorganic hybrid perovskite materials by replacing A with a cationic organic molecule, B with an inorganic post-transition metal, and X with halides, such as methylammonium tin iodide (CH 3 NH 3 SnI 3 ) and methyl ammonium lead iodide (CH 3 NH 3 PbI 3 ). 29 These organo-metal hallide (OMH) perovskite materials are engineered for diverse thin-film devices, such as solar cells, 38,39 thin-film transistors, 40 and light-emitting diodes.…”