Effect of symmetry reduction on the magnetic properties of LnIr${}_2$Si${}_2$ polymorphs

Abstract

Many tetragonal compounds LnIr${}_2$Si${}_2$ (Ln = lanthanoid) occur in two polymorphous phases and are therefore well suited to study the relationship between crystal structure and magnetic properties. We have grown GdIr${}_2$Si${}_2$ single crystals of both polymorphs from a high-temperature indium flux and investigated their anisotropic magnetic properties. The higher symmetric form with the ThCr${}_2$Si${}_2$ structure (space group $I4/mmm$) orders antiferromagnetically at $T_{\mathrm{N}}=87\mathrm{K}$ while for the lower symmetric compound in the CaBe${}_2$Ge${}_2$ structure (space group $P4/nmm$) we determined a much lower \neel temperature $T_{\mathrm{N}}=12\mathrm{K}$. Our magnetic characterization of the single crystals reveals that for both compounds the magnetic moments are aligned in the $a-a$ plane of the tetragonal lattice, but that the change of the symmetry strongly effects the inplane alignment of the moment orientation. For Ln$=$Er and Ho, we confirmed the existence of LnIr${}_2$Si${}_2$ in the space group $P4/nmm$. The magnetic properties of these lower symmetric compounds are in remarkable difference to their related compounds in the space group $I4/mmm$.

References in corpus (6)

• Field-induced transition from even to odd parity superconductivity in CeRh${}_2$As${}_2$
• Emergence of superconductivity in the canonical heavy-electron metal YbRh2Si2
• Observation of a cubic Rashba effect in the surface spin structure of rare-earth ternary materials
• Single crystal growth and characterization of GdRh${}_2$Si${}_2$
• Deterministic control of an antiferromagnetic spin arrangement using ultrafast optical excitation
• Magnetic anisotropy of YbNi4P2

Cited by in corpus (1)

• Photoemission insights into lanthanide-based crystals