Crystal structure of double oxides of the perovskite type

Magnetic Dielectric Oxides: Subsolidus Phase Relations in the BaO:Fe2O3:TiO2System

“…The oxidation state structurally characterized. Three relatively ''low-temperaof iron found in this study is similar to that reported for a ture'' phases occur in air below 1200ЊC: of Fe 3؉ in a close-packed O/Ba-O matrix and the resulting in cubic/tetragonal and hexagonal forms (5,(17)(18)(19), and opportunity to form a wide variety of layered structures with Ba 2 TiO 4 (5, 20). The latter six compounds were expected different stacking sequences and distortions from ideal pack-to occur in the BaO-Fe 2 O 3 -TiO 2 system; their crystal ing.…”

“…Many of the powder difIron substitution into the BaTiO 3 system was observed fraction patterns exhibited coincidential or nearly coinci-to stabilize the hexagonal BaTiO 3 structure (18,19) as dental strongest lines with more subtle but distinct differ-opposed to the cubic/tetragonal perovskite-like arrangeences in the weaker diffraction peaks; an ideal hexagonal ment (26,59). As seen in Fig.…”

Barium titanate twinning at low temperatures

“…The parameter changes which take place below the second transition are (i) a contraction in the c-axial direction, (ii) contraction or expansion along either a or b, and (iii) a slight change from 90 ° of the inter-axial angle between a and c. Actually, however, since two of the axes are equal, within the experimental accuracy (Rhodes, 1949) the true symmetry is orthorhombic, i.e. the lattice should be referred to the axes which form the diagonals of the monoclinic (010) face with an inter-axial angle of 90 ° (Megaw, 1946). (Note that the angle fl= 90 °, referred to in the origq_nal communication (Rhodes, 1949), indicates this angle between the orthorhombic a and c axes.)…”

Electron difference density and structural parameters in CaTiO3

“…Naray-Szabo (1943) determined its structure to be monoclinic but Megaw (1946) pointed out that an orthorhombic cell could be derived from the monoclinic lattice. Single-crystal structure analysis by Kay & Bailey (1957) confirmed the orthorhombic cell, having space group Pcmn.…”