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

电子自旋共振实验将在X- (9 GHz)和q - (34 GHz)频段进行。本文将研究掺杂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3gpa的静水压力下的测量结果进行比较。在LfeAsO1-x Fx （L = La, Ce, Pr, Nd, Sm）和二元Fe1+x se衍生体系中研究直接传导电子自旋共振，以获得传导电子系统的动态自旋磁化率，并通过自旋密度波和超导基态的线宽获得自旋晶格弛豫时间的信息。通过探索和优化不同的合成技术，可以进一步实现对超导FeSe1-y Tey和Fe1+x Se进行中子散射和红外光谱研究所需的大质量单晶的生长。

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.