Dysprosium stannides

Under standard conditions, the elements dysprosium and tin combine to form a number of intermetallic compounds, the dysprosium stannides. Dysprosium stannides with simple empirical formulas include Dy5Sn3 and DySn2, but four other intermetallics have intermediate composition. None is believed to survive temperatures higher than 1866 C, whereat Dy5Sn3 decomposes. Although dysprosium is a lanthanoid, its f orbitals likely participate in the metallic bonding: mixing dysprosium and tin releases an enthalpy quite different from mixing samarium and tin, with gadolinium and tin intermediate.

DySn2 adopts the zirconium disilicide crystal structure, and undergoes a Néel transition around 17 K. The magnetic patterning below the Néel point has periods incommensurable with the atomic unit cell, leading to a sinusoidal modulation. Theoretically, DySn2 should transition at very low temperatures to a different magnetic pattern with commensurable spatial period, but even at 1.5 K the incommensurable pattern survives.