The spin state transition in LaCoO$_{3}$; revising a revision
  Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-$L_{2,3}$ edge we reveal that the spin state transition in LaCoO$_{3}$ can be well described by a low-spin ground state and a triply-degenerate high-spin first excited state. From the temperature dependence of the spectral lineshapes we find that LaCoO$_{3}$ at finite temperatures is an inhomogeneous mixed-spin-state system. Crucial is that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum. This directly shows that the currently accepted low-/intermediate-spin picture is at variance. Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance and inelastic neutron data. 
M. W. Haverkort, Z. Hu, J. C. Cezar, T. Burnus, H. Hartmann, M.   Reuther, C. Zobel, T. Lorenz, A. Tanaka, N. B. Brookes, H....