Magnetic structure evolution of NdMnO3 derived from neutron diffraction data

The orthorhombic NdMnO3 perovskite (space group Pnma) has been studied on t he basis of magnetization and neutron powder diffraction (NPD) data. Magnet ization measurements suggest the coexistence of ferromagnetic and antiferro magnetic interactions: magnetization versus magnetic field curves present a remnant magnetization in the ordered region, which is around 1 mu(B) at T = 6 K. The thermal evolution of the magnetic structure has been followed do wn to 1.5 K from the NPD data. These measurements show that the Mn sub-latt ice becomes ordered below T-N approximate to 78 K with a spin arrangement ( C-x, F-y, 0), in such a way that a ferromagnetic component appears along th e y-direction. The Nd sub-lattice becomes ordered below T approximate to 13 K according to a ferromagnetic arrangement with the moments parallel to th e y-direction. At T = 1.5 K the magnetic moment values are 3.22(9) mu(B) fo r Mn atoms and 1.2(2) mu(B) for Nd atoms.