  The spin transition in LaCoO3 is investigated by temperature-dependent
resonant soft X-ray emission spectroscopy near the Co 2p absorption edges. This
element-specific technique is more bulk sensitive with respect to the
temperature induced spin-state of the Co3+ ions in LaCoO3 than other
high-energy spectroscopic methods. The spin transition is interpreted and
discussed with ab-initio density-functional theory within the fixed-spin moment
method, which is found to yield consistent spectral functions to the
experimental data. The spectral changes for LaCoO3 as a function of temperature
suggest a change in spin-state as the temperature is raised from 85 to 300 K
while the system remains in the same spin state as the temperature is further
increased to 510 K.
