On the magnetic structure of PrMn2O5: a neutron diffraction study

Abstract

The long-range magnetic ordering of PrMn2O5 has been studied on polycrystalline samples from neutron diffraction and specific heat measurements. The onset of antiferromagnetic ordering is observed at TN ≈ 25 K. In the temperature interval 18 K < T < 25 K the magnetic structure is defined by the propagation vector k1 = (1/2,0,0). Below 18 K, some additional magnetic satellites appear in the NPD patterns, which are indexed with k2 = (0,0,1/2). Therefore, below 18 K the magnetic structure consists of two independent magnetic domains, defined by the propagation vectors k1 and k2. The magnetic structure of the k1-domain is given by the basis vectors (Cx,0,0) and (Cx′,0,0) for Mn(4h) and Mn(4f), respectively. In the k2-domain, the magnetic structure is defined by the basis vectors (0,0,Gz) and (Fx′,Gy′,0) for Mn(4h) and Mn(4f), respectively. At T = 1.5 K, for the magnetic phase associated with k1, the magnetic moments of the Mn atoms at the 4h and 4f sites are 1.82(7) and 1.81(6) μB, respectively; for the magnetic phase associated with k2, the magnetic moments for the Mn(4h) and Mn(4f) atoms are 0.59(5) and 2.62(5) μB, respectively.