NMR Study of Magnetic State of RMn₂Intermetallic Compounds. II. R=Heavy Rare-Earth

Abstract

55 Mn spin-echo NMR spectra of RMn 2 compounds (R=heavy rare-earth) and their external field dependence have been measured in their magnetically ordered states. From the analysis of the 55 Mn hyperfine field, the Mn magnetic moments have been estimated as 2.6 and 2.5 µ B for GdMn 2 and TbMn 2 , respectively, whereas as almost zero for DyMn 2 , ErMn 2 and TmMn 2 . For DyMn 2 , a weak second 55 Mn 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 RMn 2 system: a large spacing stabilizes a substantially large Mn moment, while a small spacing makes the Mn moment unstable.