Fig. 5: H–T phase diagrams of Eu₅In₂Sb₆ for the three main crystallographic directions.

a along a axis, b along b and c along c. The faint lines and data points, reproduced¹⁶ for direct comparison, result from specific heat and magnetic measurements. Thermal expansion and magnetostriction results are indicated by ⋆ and ▵, respectively (dotted triangles for H∥b indicate results obtained with a different setup, see Supplementary Note 4 and Supplementary Fig. 5). \({H}_{{{{{\rm{m}}}}}}^{b}\) marks a metamagnetic behavior. The three regions I, II and III between H_N1 and H_N2, below H_N2, and between H_N1 and H⁺, respectively, are marked in (c). Here, H_N1 and H_N2 mark antiferromagnetic (afm) phase transitions while H⁺ signals a crossover. In (a), an anisotropic ferromagnetic polaron at zero field is sketched within afm global order, a situation expected in region I. The polarons' shortest dimension is expected along the crystallographic c direction and the Eu moments are aligned in the ab plane.