Electronic band structure and inter-atomic bonding in layered 1111-like Th-based pnictide oxides ThCuPO, ThCuAsO, ThAgPO, and ThAgAsO from first principles calculations

Autor:	Bannikov, V. V., Shein, I. R., Ivanovskii, A. L.
Rok vydání:	2011
Předmět:	Condensed Matter - Materials Science Condensed Matter - Superconductivity
Druh dokumentu:	Working Paper
Popis:	First-principles FLAPW-GGA band structure calculations were employed to examine the structural, electronic properties and the chemical bonding picture for four ZrCuSiAs-like Th-based quaternary pnictide oxides ThCuPO, ThCuAsO, ThAgPO, and ThAgAsO. These compounds were found to be semimetals and may be viewed as "intermediate" systems between two main isostructural groups of superconducting and semiconducting 1111 phases. The Th 5f states participate actively in the formation of valence bands and the Th 5f states for ThMPnO phases are itinerant and partially occupied. We found also that the bonding picture in ThMPnO phases can be classified as a high-anisotropic mixture of ionic and covalent contributions: inside [Th2O2] and [M2Pn2] blocks, mixed covalent-ionic bonds take place, whereas between the adjacent [Th2O2]/[M2Pn2] blocks, ionic bonds emerge owing to [Th2O2] \to [M2Pn2] charge transfer. Comment: 16 pages, 6 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1104.3434 Zobrazit plný text záznamu View this record from Arxiv