  Although the parent iron-based pnictides and chalcogenides are itinerant
antiferromagnets, the use of local moment picture to understand their magnetic
properties is still widespread. We study magnetic Raman scattering from a local
moment perspective for various quantum spin models proposed for this new class
of superconductors. These models vary greatly in the level of magnetic
frustration and show a vastly different two-magnon Raman response. Light
scattering by two-magnon excitations thus provides a robust and independent
measure of the underlying spin interactions. In accord with other recent
experiments, our results indicate that the amount of magnetic frustration in
these systems may be small.
