Dimensionality Controlled Spin State Transition in LaCoO3/LaAlO3 Superlattices
We investigated the electronic structure of [(LaCoO3)n(LaAlO3)n]8 (n = 2, 6, and 10) superlattices using x-ray absorption spectroscopy, and optical conductivity. High quality superlattices samples were fabricated by pulsed laser deposition. X-ray diffraction and X-ray absorption spectroscopy experiments indicated stoichiometric and coherent growth of high quality superlattices.
Spectroscopic investigation revealed the critical role of dimensionality on the electronic structure of ultra-thin LaCoO3 layers. The system with low dimensional LaCoO3 exhibits a low spin state with larger optical gap due to the quantum confinement. Dynamic mean field calculation clearly simulated the critical role of dimensionality on the spin state and electronic structure of LaCoO3.