Sc2TiO5, an entropy-stabilized pseudobrookite-type compound

✍ Scribed by Kolitsch, Uwe ;Tillmanns, Ekkehart

• Book ID: 104480146
• Publisher: International Union of Crystallography
• Year: 2003
• Tongue: English
• Weight: 251 KB
• Volume: 59
• Category: Article
• ISSN: 1600-5368
• DOI: 10.1107/s1600536803003544

✦ Synopsis

Discandium(III) titanate(IV), Sc 2 TiO 5 , prepared by the ¯ux method, has a pseudobrookite-type structure. The Sc and Ti atoms are partially disordered on the two octahedrally coordinated metal (M) sites (Wyckoff designations 8f and 4c in space group Cmcm). The most probable cation distribution suggests the approximate structural formula [8f] (Sc 0.6 ,Ti 0.4 ) 2

[4c] (Sc 0.8 Ti 0.2 )O 5 , in agreement with earlier observations of a preference of Ti for the more distorted 8f site in isotypic A III 2 B IV O 5 compounds. The average MÐO bond lengths for the 8f and 4c sites are 2.059 and 2.095 A Ê , respectively. The strongly distorted octahedra share edges to form trioctahedral units, which are linked into in®nite double chains along c. Further sharing of octahedral edges results in a three-dimensional framework. All atoms are on special positions. An Al-bearing variety of Sc 2 TiO 5 has Al preferentially incorporated on the 4c site.