75As NMR study of the ternary iron arsenide BaFe2As2

TL;DR

This study uses 75As-NMR to investigate the magnetic properties of BaFe2As2, revealing a first-order magnetic transition at 131 K associated with a spin density wave, with specific relaxation behaviors.

Contribution

First detailed 75As-NMR analysis of BaFe2As2 revealing the nature of its magnetic transition and spin dynamics.

Findings

Magnetic transition at ~131 K linked to spin density wave

Transition likely of first order based on internal magnetic field data

Absence of critical-slowing-down in spin-lattice relaxation rate

Abstract

We report 75As-NMR measurements of the ternary iron arsenide BaFe2As2. 75As-NMR spectra clearly revealed that magnetic transition occurs at around 131 K in our samples, which corresponds to the emergence of spin density wave. Temperature dependence of the internal magnetic field suggests that the transition is likely of the first order. The critical-slowing-down phenomenon in the spin-lattice relaxation rate 1/T1 is not pronounced in this material.