Magnetic structure evolution of NdMnO3 derived from neutron diffraction data

The orthorhombic NdMnO3 perovskite (space group Pnma) has been studied on the basis of magnetization and neutron powder diffraction (NPD) data. Magnetization measurements suggest the coexistence of ferromagnetic and antiferromagnetic interactions: magnetization versus magnetic field curves present a remnant magnetization in the ordered region, which is around 1 μB at T = 6 K. The thermal evolution of the magnetic structure has been followed down to 1.5 K from the NPD data. These measurements show that the Mn sub-lattice becomes ordered below TN approx.= 78 K with a spin arrangement (Cx ,Fy,0), in such a way that a ferromagnetic component appears along the y-direction. The Nd sub-lattice becomes ordered below T approx.= 13 K according to a ferromagnetic arrangement with the moments parallel to the y-direction. At T = 1.5 K the magnetic moment values are 3.22(9) μB for Mn atoms and 1.2(2) μB for Nd atoms. (author)