Magnetic and quadrupolar interactions in NdB₆

By analysis of the excitation spectrum of NdB₆, we extract the intersite magnetic interactions. The Néel temperature T_N = 7.9 K is obtained by using the value of the intersite interaction deduced from the fit, which compares favourably with the experimental value T_N ≃ 8 K. We take into consideration a ferroquadrupolar interaction g′₃ in the analysis, and obtain g′₃ = 107 mK, which agrees well with the experimental value of about 100 mK. The ferroquadrupolar interaction results in a gap in the excitation spectrum observed in the experiment.