The Crystal Structure of K2Ti2O5.

Low‐temperature controllable calcination syntheses of potassium dititanate

“…2, respectively, indicating that estimated starting generation temperatures for preparing potassium dititanate from anatase and TiO 2 ⅐nH 2 O are 508 and 295°C, respectively. These estimated temperatures are far lower than the reported temperature of 1000°C (Andersson, 1960(Andersson, , 1961Fujiki, 1982Fujiki, , 1988Kudo, 1993Kudo, , 1997bKudo, , 1998Ogawa, 1995;Shibata, 1987;Shimizu, 1980;Yagi, 2001).…”

“…Since the first discovery of potassium dititanate (Andersson, 1960), much attention has been given to calcination syntheses of potassium dititanate (K 2 Ti 2 O 5 ) from crystalline precursors of anatase and rutile at T Ͼ 1000°C or to ion-exchange syntheses of proton potassium dititanate (K 2Ϫx H x Ti 2 O 5 ) and hydrous potassium dititanate (K 2 Ti 2 O 5 ⅐xH 2 O) from potassium dititanate (Andersson, 1960(Andersson, , 1961Clearfield, 1988;Fujiki, 1982Fujiki, , 1988Kudo, 1993Kudo, , 1997bKudo, , 1998Ogawa, 1995;Shibata, 1987;Shimizu, 1980;Yagi, 2001). However, systematic studies on modulations of morphologies, sizes, water contents, and crystallinities of potassium dititanate and corresponding reaction conditions are still inadequate.…”

Alkali titanoniobates. The crystal structures of KTiNbO5and KTi3NbO9

“…Both V~O5 (BystrSm, Wilhelmi & Brotzen, 1950;Bachmarm, Ahmed & Barnes, 1961) and K2Ti205 (Andersson & Wadsley, 1961) are layer substances with sheets of the same composition if not the same charge, but in these cases V 5+ and Ti 4+ are in fivefold coordination, and their structures have few features of any kind in common with that of KTiNbOs. It would not be surprising if the alkali metals were exchangeable for other ions or long-chain aliphatic groups, a feature of a wide variety of layer compounds, from silicate minerals to alkali titanates and vanadates.…”

“…The formulae of these hypothetical substances can be readily established by counting atoms within the unit cells, and the problem is then to make and to identify them. The octahedrally coordinated metals will need to have valencies in between four and five, and in view of the readiness with which Ti 4+ and Nb 5+ form pseudobinary oxides of mixed valency (Wadsley, 1961) the compounds could perhaps be sought as ternary titanoniobates. The presence of these two elements as isomorphous substituents will ensure close control of the valency and of the overall composition, if single phases are formed by reaction of the component oxides in the solid state or by fusion.…”

Low temperature synthesis of tetragonal BaTiO3 by using molten salt

“…18) We attempted lower temperature synthesis of BT powder by using a reactive starting compound in molten salt. A layered K 2 Ti 2 O 5 19) was selected as a starting compound because the arrangement of Ti atoms in K 2 Ti 2 O 5 was similar to that of the perovskite-type structure and mixed barium salts (BaCl 2 + Ba(NO 3 ) 2 ) with the molar ratio of 1:1 was used because of the lower melting point. In this paper we will describe synthesis of the tetragonal BT powder by using molten salt and its properties.…”