Thulium magnetic susceptibility

In the case of thulium compounds TmSe and TmTe and YI3AI3, distinct multiplet structures due to divalent and trivalent thulium are seen in the 4f region [38]. The multiplet structure in TmTe is more distinct than in the case of TmSe in agreement with magnetic susceptibility data, (i.e.) magnetic moment of TmTe is smaller than that of TmSe. 

Using calorimetry, Berezovskii et al. (1991) determined the second-order Neel transition to be at 56.6 K and the first-order Curie-type transition to be at 32.6 K. These values were satisfactorily confirmed by Astrom et al. (1991) using a combination of magnetization, AC susceptibility, and calorimetry. In spite of these transitions, thulium exists in a close-packed hexagonal stmcture up to the melting point selected by Gschneidner (1990) as 1818 K. 

---