Band edge singularities and density of states in YTaO4 AND YNbO4
We study the structural and electronic properties of YTaO4 and YNbO4 by means of accurate first-principle total energy calculations. The calculations are based on density functional theory (DFT). The total energy, electronic band structure, and density of states are calculated via th...
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| Autores principales: | , |
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
D.Ghitu Institute of Electronic Engineering and Nanotechnologies
2011
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/3afc76f535264911bff0d87584315430 |
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| Sumario: | We study the structural and electronic properties of YTaO4 and YNbO4 by means of
accurate first-principle total energy calculations. The calculations are based on density functional
theory (DFT). The total energy, electronic band structure, and density of states are calculated via
the full potential linear-augmented plane wave approach, as implemented in the WIEN2K code,
within the framework of DFT. The results show that the valence bands of tantalate and niobate
systems are from O 2p states. Conduction bands are divided into two parts. The lower conduction
band is mainly composed of Ta 5d or Nb 4d states and the upper conduction bands involve
contribution mainly from Y 4d states of YTaO4 or YNbO4. The efficient band gaps in yttrium
tantalate and niobate are determined about 4.8 and 4.1 eV, respectively. The agreement between
the calculations and the experimental data is excellent. The efficient band gap and a simple model
illustrating excitation and emission process in considered host lattices are discussed.
Keywords: Electronic properties; YTaO4; YNbO4; Luminescence
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