Abstract

Strontium lanthanum aluminate (SrLaAlO₄) belongs to a wide family of compounds with the general formula ABCO₄ (where A denotes an alkaline earth cation: B denotes Y. Sc or a trivalent rare earth element and C denotes Al, Ga or a transition metal ion). This material crystallises in the perovskite phase, with tetragonal K₂NiF₄ structure having space group 14/mmm. The structure is composed of CO₆ layers in the ab plane. The C cations are surrounded by six oxygens and sit in slightly distorted octahedral sites. Between these layers, the A cations and trivalent B cations are randomly distributed in nine co-ordinated sites of C_4v symmetry. The random distribution of Sr²⁺ and La³⁺ ions leads to a structural disorder that causes inhomogeneous broadening of the spectral lines of rare-earth ions doped into these crystals.

© 1998 IEEE