The discovery of superconductivity in MgB2 has initiated a frantic activity worldwide both theoretically and experimentally in order to understand its physical properties and their implications to the observed superconductivity, since the compound is very promising for practical applications. However, despite the great progress to understand the properties of MgB2, there are open questions that have to be addressed concerning the temperature and pressure response of the E2g phonon mode, which is responsible for the superconductivity in MgB2.
On the other hand, these systems exhibit unique properties and atomic substitutions may influence the basic properties of MgB2 superconductor making it appropriate for potential applications. In analogy with the high Tc cuprates we will use an alternative approach for the understanding of the properties of MgB2 by following the evolution of properties of doped MgB2-systems under external perturbations like temperature or pressure. Therefore, we plan to extensively study b y means of Raman scattering at ambient conditions as well as under high pressure or low temperatures the vibrational and the super-conducting properties of various doped MgB2-based superconductors.
These compounds are synthesized and characterized with various experimental techniques during my initial fellowship in Prof. K. Prassides research group (University of Sussex, UK). Also, we intent to synthesize novel mixed alkali/transition metal borides with stoichiometry, (A,TM)xMg1.xB2 where A=Li+, Na+ and TM=Z n2+, AI3+. By employing the Raman spectroscopic technique on selected doped MgB2 compounds as a function of both temperature and pressure a wealth of information can be provided about:
(i) the elucidation of the role of the E2g mode in the super-conducting process,
(ii) how the observed decrease of Tc upon doping is related to the reduction of the electron-phonon coupling and the induced changes of the Fermi surface
Field of science
- /engineering and technology/materials engineering/composites
- /natural sciences/physical sciences/electromagnetism and electronics/electrical conductivity/superconductor
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