The structural properties of the layered oxides Ba2SnO4 and Sr2SnO4 have been studied as a function of temperature by high resolution powder neutron diffraction. As a result of excellent size matching between the SnO2 and Ba2O2 layers, Ba2SnO4 adopts the tetragonal K2NiF4 structure (space group I4/mmm) and undergoes no structural phase transition on cooling. Sr2SnO4, on the other hand, is orthorhombically distorted, (b - a)/(b + a) = 7.2(7) × 10-4 at ambient temperature (space group Bmab) as a result of the co-operative rigid tilt of the corner-sharing SnO6 octahedra, which relieves the compressive stress of the SnO2 layers. Upon cooling, it undergoes a phase transition to a primitive tetragonal phase (space group P42/ncm) which is characterised by a different rotational mode of distortion.
|Number of pages||5|
|Journal||Journal of the Chemical Society - Faraday Transactions|
|Publication status||Published - 1996 Jun 21|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry