Magnetic structure of TbD2—A neutron diffraction study

Abstract

Terbium dideuteride has been examined by elastic neutron scattering. Crystallographic parameters have been determined at 300 and 77 K. It was found that Tb${\mathrm{D}}_2$ undergoes a para- to antiferromagnetic transition at $T_N=17.2\mathrm{}\left(3\right)\mathrm{}$ K. The magnetic structure at 4.6 K was determined and found to belong to the monoclinic space group $\frac{C_{2c}2}{m^{\prime }}$. The magnetic moment per ${\mathrm{Tb}}^{3+}$ ion is 7.6(3) ${\mathrm{\mu }}_{\mathit{B}}$ at 4.6 K. The reduction from the free-ion value of 9.0 ${\mathrm{\mu }}_{\mathit{B}}$/${\mathrm{Tb}}^{3+}$ is due to crystalline electric field effects that are also apparent in the temperature dependence of the sublattice magnetization.