Spectroscopic and analytical studies at high temperatures using novel experimental and theoretical techniques

• Research unit: COST
• Project number: C96.0035

Key words (English)

Photoelectron spectroscopy; amorphous metals; binary alloys; electronic structure

Research programs (English)

COST-Action D6 - Chemical processes and reactions under extreme or non-classic conditions

Short description (English)

See abstract

Partners and International Organizations (English)

B, CH, CZ, D, DK, E, F, FIN, GR, H, I, NL, P, PL, S, SI, SK

Abstract (English)

The continuous concentration dependent metal to non-metal transition of alloys of alkali metals with elements of group IVb has been investigated with ultraviolet photoelectron spectroscopy (UPS) for the systems Na-Sn and K-Sn. The non-metallic regime is dominated by Zintl anions - one or more group IVb atom with excess negative charge - surrounded by alkali atoms. The chemical bond between the alkali and the group IVb atom in this case is ionic rather than metallic. This causes the opening of a pseudo gap in the electronic density of states at the Fermi energy Ef . The samples were prepared as thin films at 80 K by co-evaporation. The continuity of the transition and its good agreement with previous measurements of the liquid systems suggest for the quenched films a disordered structure with predominant Zintl ions of fragments thereof which is very similar to the structure of the liquid systems.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C96.0035