NMR Study of ¹⁵⁹Tb in Tb_1−xGd_xMn₂ and Tb_1−xLu_xMn₂ Pseudobinary Intermetallic Compounds

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Spin echo NMR measurements on ¹⁵⁹Tb have been done in magnetically ordered state of the cubic Laves phase compounds Tb_1−xGd_xMn₂ with 0≤x≤0.8 and Tb_1−xLu_xMn₂ with 0≤x≤0.25. In the Tb_1−xGd_xMn₂ compounds, the magnetic hyperfine field of Tb decreases from 3365 kOe for x=0.8 to 3336 kOe for x=0 and the magnitude of the electric quadrupole splitting of ¹⁵⁹Tb is nearly constant within experimental uncertainty. In the Tb_1−xLu_xMn₂ compounds, the transferred hyperfine field at Tb from the neighboring rare earth ions was estimated to be +20 kOe per rare earth spin. From the hyperfine field analysis of Tb in these compounds, the orbital polarization contribution is expected to the self polarization field due to the conduction electron polarization by the parent Tb³⁺ ion. An external magnetic field dependence of the spin echo intensity of ¹⁵⁹Tb in TbMn₂ was also investigated.