Year: 2024
Type: article
Abstract: Using spectroscopic ellipsometry, we studied the optical conductivity of LaCoO 3 with various degrees of strain. The optical response of the compressively strained LaCoO 3 film is qualitatively similar to the one of the unstrained LaCoO 3 polycrystalline sample and exhibits a redistribution of the spectral weight between ∼ 0.2 and 6 eV, which is most likely related to the thermal excitation of the high-spin (HS) states. The optical response of the ferromagnetic (FM) tensile strained film exhibits clear signatures of the FM state. Below the Curie temperature T c = 82 K, a spectral weight transfer sets on from high energies (between 3.3 and 5.6 eV) to low energies (between 0.2 and 3.3 eV). The temperature dependence of the low-energy spectral weight can be understood in the framework of the HS biexciton model of Sotnikov [] as corresponding to the increase of the concentration of the HS states that are stabilized below T c . The magnitude of the redistribution of the spectral weight due to the formation of the FM state is sizable and corresponds to 0.009 e per Co ion. We discuss it in terms of the effective kinetic energy of Co 3 d bands. Published by the American Physical Society 2024
Authors: F. Abadizaman, D. Munzar, M. Kiaba, A. Dubroka
Institutions: Masaryk University, Brno University of Technology
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4405736842