Neutron-diffraction study of the magnetic structures in $R{\mathrm{D}}_2$, ($R=\mathrm{T}\mathrm{b},\mathrm{ }\mathrm{D}\mathrm{y},\mathrm{ }\mathrm{H}\mathrm{o},\mathrm{ }\mathrm{and}\mathrm{ }\mathrm{Er}$)

The magnetic structures in cubic $R{\mathrm{D}}_2$ ($R=\mathrm{T}\mathrm{b},\mathrm{ }\mathrm{D}\mathrm{y},\mathrm{ }\mathrm{H}\mathrm{o},\mathrm{ }\mathrm{and}\mathrm{ }\mathrm{Er}$) have been studied with neutron diffraction. The dideuterides of Tb, Dy, and Ho have modulated magnetic structures with a periods of $\frac{4a_0}{\sqrt{11}}$ along [113]. This modulation is commensurate with the crystal lattice and leads to a nonprimitive cubic magnetic lattice with a translation of $4a_0$. The ionic magnetic moments are of a single magnitude, independent of position. The magnetic structure of Er${\mathrm{D}}_2$ contains both a commensurate component that belongs to a cubic magnetic lattice with lattice parameter $4a_0$ and an additional incommensurate component. An intermediate magnetic structure of the type found in Er${\mathrm{D}}_2$ appears in the Tb, Dy, and Ho compounds above $T_N$, but disappears below $T_N$, giving way to the apparently more stable, commensurate structure mentioned above.