Progressive slowing down of spin fluctuations in underdoped LaFeAsO${}_{1-x}$F${}_x$

F. Hammerath, U. Gräfe, H. Kühne +7

The evolution of low-energy spin dynamics in the iron-based superconductor LaFeAsO${}_{1-x}$F${}_x$ was studied over a broad doping, temperature, and magnetic field range (x = 0 - 0.15…