Neutron Scattering Study of the Magnetic Structure of NdFeAsO

We report the neutron scattering studies of the non-superconducting NdFeAsO. In NdFeAsO, there is a tetragonal to orthorhombic structural transition at Ts$\approx$150 K, where an anomaly in resistivity also occurs. A long range magnetic order with the wave-vector (1/2, 1/2, 0)$_T$ forms below T$_N$=1.96 K. This long range order is dominated by the rare earth Nd ions, however, both the Nd and smaller Fe moments contribute to the antiferromagnetic structure. No LaFeAsO-like SDW ordering below Ts was observed in the initial study[1]. We will address the difference in magnetic structures.