We report on neutron scattering studies of a rare earth intermetallic
compound ErNi2βGe2β. Polarized neutron scattering experiments revealed
that the magnetic ordered moment m lies in ab-plane. Taking account of
a lack of the third higher harmonic reflection, ErNi2βGe2β is
considered to have a helical magnetic structure. The magnetic scattering
profiles along the [100]β- and the [110]β-directions are well
described by the sum of Gaussian and modified-Lorentzian terms, even far below
TNβ, indicating that short-range orders coexist with a
long-range order. Interestingly, the modified-Lorentzian-type diffuse
scattering is not present in the profiles along the [001]β-direction.
The anisotropy of the diffuse scattering suggests that the short-range-order
consists of one dimensional long-range helices along the c-axis.Comment: 4 pages, to be published in J. Phys.: Condens. Matter (HFM2008