Description
The rare-earth ion garnets (ReIG) thin films have been studied recently due to potential applications in spintronics [1]. We have demonstrated previously where the polarized neutron reflectometry (PNR) was used to study the magnetic proximity behavior at interfaces of Pt/Tb3Fe5O12/Gd3Ga5O12 (111) thin films [2]. In this study, the electronic properties, microstructures, and oxidation states of the garnet thin film system (Eu3Fe5O12/Tb3Fe5O12/Gd3Ga5O12 (111)) were investigated. The Cambridge Sequential Total Energy Package (CASTEP) [3] based on density functional theory (DFT) was applied to calculate the energy band structure as well as density of states (DOS) of Eu3Fe5O12, Tb3Fe5O12, and Gd3Ga5O12, respectively. The first-principles calculation indicates that the band gap of Gd3Ga5O12 has been determined to be Eg= 3.5 eV (Eg= 2.3 eV for Eu3Fe5O12 and Eg= 3.5 eV for Tb3Fe5O12) and it is contributed from Gd-3d and O-2p orbitals. Results characterized by transmission electron microscopy (TEM) indicate that an epitaxial growth was found in a Eu3Fe5O12 (20 nm)/Tb3Fe5O12 (30 nm) thin film deposited on Gd3Ga5O12 (111) single crystal substrates. In addition, results characterized by X-ray photoelectron spectroscopy (XPS) indicate that the Eu3Fe5O12/Tb3Fe5O12 thin film consisted of Eu3+ and Tb3+ in the Eu3Fe5O12 and Tb3Fe5O12 layer, respectively. The peak shift as well as peak intensity variations in the Fe spectra imply that the changes in Fe valence and oxygen vacancies may be presence in the thin film system. This in turn will strongly affect the respected properties.
Research was supported by NSTC of Taiwan and Hong Kong Research Grants Council.
[1] P. G. Li et al., J. Magn. Magn. Mater 592, 171785 (2024).
[2] R. Yadav et al., Phys. Rev. Mater 7, 124407 (2023).
[3]https://www.3ds.com/products/biovia/materials-studio
| I am the presenting author | Yes |
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