Magneto-capacitive coupling and hybridization driven structural anomalies in Spinels

本研究的目的是阐明尖晶石中磁容效应的耦合机制及其应用。具有磁性、介电和晶格自由度共存和相互耦合的多铁性是目前感兴趣的中心。虽然实际问题涉及耦合常数和特征温度区域的最大化，但也存在与小能量尺度的存在、局部扭曲的影响以及电子结构的动态变化有关的基本问题。在这个项目中，我们将进行拉曼散射、超声波光谱和单晶的制备。拉曼散射对局域的极性扭曲特别敏感。利用超声光谱学将研究结构和电子弛豫过程。样品还将根据应用情况进行掺杂和优化。

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.