NMR Study of Magnetic State of RMn₂ Intermetallic Compounds. II. R=Heavy Rare-Earth

抄録

⁵⁵Mn spin-echo NMR spectra of RMn₂ compounds (R=heavy rare-earth) and their external field dependence have been measured in their magnetically ordered states. From the analysis of the ⁵⁵Mn hyperfine field, the Mn magnetic moments have been estimated as 2.6 and 2.5 μ_B for GdMn₂ and TbMn₂, respectively, whereas as almost zero for DyMn₂, ErMn₂ and TmMn₂. For DyMn₂, a weak second ⁵⁵Mn NMR signal has been observed, indicating the Mn moment of 2.1 μ_B. Concludingly, the onset of the Mn moment is very sensitive to the interatomic spacing of Mn atoms in the RMn₂ system: a large spacing stabilizes a substantially large Mn moment, while a small spacing makes the Mn moment unstable.