Lattice dynamics of superionic copper selenide

• Applicant: Professor Dr.-Ing. Hartmut Fueß
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2001 to 2004
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5307162

Copper selenide "Cu2 minus delta Se" has a mixed ionic-electronic conductivity with a broad range of homogeneity and belongs to the degenerate p-type semiconductors. The high temperature modification of copper selenide is a superionic conductor with structural disorder. A peculiarity of superionic conductors is the presence of the low energy modes in the frequency spectrum. The energy of these modes lies in the range of 2-10 meV. The origin of this low frequency anomaly in superionic conductors is not understood yet although a strong correlation between the superionic phase transition and the presence of the low-energy mode is assumed. At present, the main electro-physical properties of "Cu2 minus delta Se" are known but the crystal structure and lattice dynamics of "Cu2 minus delta Se" will be investigated.

• DFG Programme: Research Grants
• Participating Person: Privatdozent Dr. Thomas Wieder