Itinerant and localized magnetism in Fe based superconductors - Electron Spin Resonance spectroscopy and single crystal growth

X波段(9 GHz)和Q波段(34 GHz)的电子自旋共振实验将在铁粒子及其相关系统中进行。我们将研究掺杂EuFe2As2基材料的局域磁矩与传导电子系统的耦合，并与EuFe2As2在高达3 GPa静水压下的测量结果进行比较。研究了LFeAsO1-xFx(L=La，Ce，Pr，NdSm)和二元Fe1+xSe衍生系统的直接传导电子自旋共振，以获得传导电子系统的动态自旋极化率，并通过自旋密度波和超导基态的线宽得到自旋-晶格弛豫时间的信息.对于超导FeSe1-yTey和Fe1+xSe的中子散射和红外光谱研究所需的大尺寸高质量单晶的生长是通过探索和优化不同的合成工艺来实现的进一步目标。

Electron spin resonance experiments at X- (9 GHz) and Q-band (34 GHz) frequencies will be performed in iron pnictides and related systems. The coupling of localized magnetic moments and the conduction electron system will be studied in doped EuFe2As2-based materials and compared to measurements of EuFe2As2 under hydrostatic pressure up to 3 GPa. The direct conduction electron spin resonance will be investigated in the LfeAsO1-x Fx (L = La, Ce, Pr, Nd, Sm) and the binary Fe1+x Se-derived systems to access the dynamic spin susceptibility of the conduction electron system and get information on the spin-lattice relaxation time via the linewidth in the spin-density-wave and superconducting ground state. The growth of large high-quality single crystals necessary for neutron scattering and infrared spectroscopy studies of superconducting FeSe1-y Tey and Fe1+x Se is a further goal to be reached by the exploration and optimization of different synthesis techniques.