A combination of synchrotron x-ray, neutron powder-diffraction, magnetization, heat-capacity, and electrical-resistivity measurements reveals that NdMnAsO is an antiferromagnetic semiconductor with large Neel temperature [TN =359 (2) K]. At room temperature the magnetic propagation vector k=0 and the Mn moments are directed along the crystallographic c axis [m Mn =2.41 (6) µB]. Upon cooling a spin-reorientation (SR) transition of the Mn moments into the ab plane occurs (TSR =23 K). This coincides with the long-range ordering of the Nd moments, which are restricted to the basal plane. The magnetic propagation vector remains k=0. At base temperature (1.6 K) the fitted moments are mab,Mn =3.72 (1) µB and mab,Nd =1.94 (1) µB. The electrical resistivity is characterized by a broad maximum at 250 K, below which it has a metallic temperature dependence but semiconducting magnitude (?250 K =50 Ocm, residual resistivity ratio=2), and a slight upturn at the SR transition. © 2010 The American Physical Society.
|Journal||Physical Review B: Condensed Matter and Materials Physics|
|Publication status||Published - 29 Nov 2010|