Magneto-capacitive coupling and hybridization driven structural anomalies in Spinels

• Applicant: Professor Dr. Peter Lemmens
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2007 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 53449689

The aim of our study is to clear up the coupling mechanism and the application of magnetocapacitive effects in spinels, as e.g. CdCr2S4. Multiferroics, with coexistence and mutual coupling of magnetic, dielectric and lattice degrees of freedom are in the centre of present interest. While practical questions involve the maximisation of both coupling constants and characteristic temperature regimes, there are also fundamental issues related to the existence of small energy scales, the effect of local distortions, and the dynamic variation of the electronic structure. Within this project we will perform Raman scattering, ultrasound spectroscopy and preparation of single crystals. Raman scattering is especially sensitive to local polar distortions. Using ultrasound spectroscopy structural and electronic relaxation processes will be studied. Samples will also be doped and optimized with respect to applications.

• DFG Programme: Research Grants
• International Connection: Moldova
• Participating Person: Dr. Vladimir Tsurkan