Neutron-scattering study of magnetism in Nd2BaNiO5.

Abstract

Single crystals of the linear chain phase ${\mathrm{Nd}}_{2}$${\mathrm{BaNiO}}_{5+\mathrm{\ensuremath{\delta}}}$ [\ensuremath{\delta}=0.005(1)] have been prepared and the magnetism studied by neutron scattering. The Ni-O chain direction is along the short axis a. Long-range antiferromagnetic order sets in below ${\mathit{T}}_{\mathit{N}}$=48 K with Nd and Ni moments parallel to [001]. The ${\mathrm{Nd}}_{2}$${\mathrm{BaNiO}}_{5}$ magnetic cell is doubled along a and c relative to the chemical unit cell. The magnitude of the moments at 4.9 K is 2.7(2) and 1.2(1)${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$ for Nd and Ni, respectively.