We present powder and single-crystal x-ray diffraction data as evidence for a monoclinic distortion in the low-spin (S = 0) and intermediate spin states (S = 1) of LaCoO3. The alternation of short and long bonds in the ab plane indicates the presence of eg orbital ordering induced by a cooperative Jahn-Teller distortion. We observe an increase of the Jahn-Teller distortion with temperature in agreement with a thermally activated behavior of the Co3+ ions from a low-spin ground state to an intermediate-spin excited state.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 18 Jun 2003