engleski

Magnetic ordering and charge dynamics in kappa-(BEDT-TTF)2Cu[N(CN)2]Cl

\begin{; ; ; ; abstract}; ; ; ; The Mott insulator $\kappa$-(BE\-DT\--TTF)$_2$\-Cu\-[N\-(CN)$_{; ; ; ; 2}; ; ; ; $]Cl consists of molecular dimers arranged on an anisotropic triangular lattice. At low temperatures a pronounced dielectric anomaly is observed and eventually a canted antiferromagnetic ground state forms. Optical spectroscopy clearly rules out charge imbalance and the existence of quantum electric dipoles with a dipolar spin coupling. Here we suggest a novel form of spin-charge coupling where the prominent in-plane dielectric response in $\kappa$-(BE\-DT\--TTF)$_2$\-Cu\-[N\-(CN)$_{; ; ; ; 2}; ; ; ; $]Cl is explained by short-range discommensurations of the antiferromagnetic phase in the temperature range $30 < T < 50$~K, and by relaxation of charged domain walls in the ferromagnetic structure at lower temperatures. \end{; ; ; ; abstract}; ; ; ;

magnetic and charge oredring; ferroelelectricity; multiferroic; domain walls; spin-charge coupling; quantum eletric dipoles

nije evidentirano