Tensile-strain-dependent spin states in epitaxial LaCoO3 thin films



Y. Yokoyama, Y. Yamasaki, M. Taguchi, Y. Hirata, K. Takubo, J. Miyawaki, Y. Harada, D. Asakura, J. Fujioka, M. Nakamura, H. Daimon, M. Kawasaki, Y. Tokura, and H. Wadati



The spin states of Co3+ ions in perovskite-type LaCoO3, governed by complex interplay between the electron-lattice interactions and the strong electron correlations, still remain controversial due to the lack of experimental techniques which can detect directly. In this letter, we revealed the tensile-strain dependence of spin states, i.e. the ratio of the high- and low-spin states, in epitaxial thin films and a bulk crystal of LaCoO3 via resonant inelastic soft x-ray scattering. The tensile-strain as small as 1.0\% was found to realize different spin states from that in the bulk.


Physical Review Letters: